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Condensed Matter

New submissions

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New submissions for Thu, 23 Nov 17

[1]  arXiv:1711.07981 [pdf, other]
Title: Two-dimensional Ising model on random lattices with constant coordination number
Comments: LaTeX, 19 pages, 12 figures
Subjects: Statistical Mechanics (cond-mat.stat-mech)

We study the two-dimensional Ising model on a network with a novel type of quenched topological (connectivity) disorder. We construct random lattices of constant coordination number and perform large scale Monte Carlo simulations in order to obtain critical exponents using finite-size scaling relations. We find disorder-dependent effective critical exponents, similar to diluted models, showing thus no clear universal behavior. Considering the very recent results for the two-dimensional Ising model on proximity graphs and the coordination number correlation analysis suggested by Barghathi and Vojta (2014), our results indicate that the planarity and connectedness of the lattice play an important role on deciding whether the phase transition is stable against quenched topological disorder.

[2]  arXiv:1711.07988 [pdf, other]
Title: Coupling two order parameters in a quantum gas
Comments: 8 pages, 7 figures
Subjects: Quantum Gases (cond-mat.quant-gas); Materials Science (cond-mat.mtrl-sci); Strongly Correlated Electrons (cond-mat.str-el); Quantum Physics (quant-ph)

Controlling matter to simultaneously support multiple coupled properties is of fundamental and technological importance. For example, the simultaneous presence of magnetic and ferroelectric orders in multiferroic materials leads to enhanced functionalities. In high-temperature superconductors, intertwining between charge- and spin-order can form superconducting states at high transition temperatures. However, pinning down the microscopic mechanisms responsible for the simultaneous presence of different orders is difficult, making it hard to predict the phenomenology of a material or to experimentally modify its properties. Here we use a quantum gas to engineer an adjustable interaction at the microscopic level between two orders, and demonstrate scenarios of competition, coexistence and coupling between them. In the latter case, intriguingly, the presence of one order lowers the critical point of the other. Our system is realized by a Bose-Einstein condensate which can undergo self-organization phase transitions in two optical resonators, resulting in two distinct crystalline density orders. We characterize the intertwining between these orders by measuring the composite order parameter and the elementary excitations. We explain our results with a mean-field free energy model, which is derived from a microscopic Hamiltonian. Our system is ideally suited to explore properties of quantum tricritical points as recently realized in and can be extended to study the interplay of spin and density orders also as a function of temperature.

[3]  arXiv:1711.07989 [pdf, other]
Title: Multiferroic Quantum Criticality
Comments: 7 pages, 4 figures
Subjects: Materials Science (cond-mat.mtrl-sci); Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el)

The zero-temperature limit of a continuous phase transition is marked by a quantum critical point, which is associated with exotic physics that extends to elevated temperatures. Magnetic quantum criticality is now well known, and has been explored in systems ranging from heavy fermion metals to quantum Ising materials. More recently, ferroelectric quantum critical behaviour has been established, motivating a flurry of research investigating its consequences. Here, we introduce the concept of multiferroic quantum criticality, in which both magnetic and ferroelectric quantum criticality occur in the same system. We develop the phenomenology of multiferroic quantum critical behaviour, describe the associated experimental signatures, and propose material systems and schemes to realize it.

[4]  arXiv:1711.07997 [pdf, other]
Title: Superconductiving fluctuations at arbitrary disorder strength
Comments: 17 pages, 7 figures
Subjects: Superconductivity (cond-mat.supr-con); Disordered Systems and Neural Networks (cond-mat.dis-nn); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

We study the effect of superconducting fluctuations on the conductivity of metals at arbitrary temperatures $T$ and impurity scattering rates $\tau^{-1}$. Using the standard diagrammatic technique but in the Keldysh representation, we derive the general expression for the fluctuation correction to the dc conductivity applicable for any space dimensionality and analyze it the case of the film geometry. We observe that the usual classification in terms of the Aslamazov-Larkin, Maki-Thompson and density-of-states diagrams is to some extent artificial since these contributions produce similar terms, which partially cancel each other. In the diffusive limit, our results fully coincide with recent calculations in the Keldysh technique. In the ballistic limit near the transition, we demonstrate the absence of a divergent term $(T\tau)^2$ attributed previously to the density-of-states contribution. In the ballistic limit far above the transition, the temperature-dependent part of the conductivity correction is shown to scale roughly as $T\tau$.

[5]  arXiv:1711.08005 [pdf]
Title: Imaging bulk and edge transport near the Dirac point in graphene moiré superlattices
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Van der Waals structures formed by aligning monolayer graphene with insulating layers of hexagonal boron nitride exhibit a moir\'e superlattice that is expected to break sublattice symmetry. Despite an energy gap of several tens of millielectron volts opening in the Dirac spectrum, electrical resistivity remains lower than expected at low temperature and varies between devices. While subgap states are likely to play a role in this behavior, their precise nature is unclear. We present a scanning gate microscopy study of moir\'e superlattice devices with comparable activation energy but with different charge disorder levels. In the device with higher charge impurity (~${10}^{10}$ $cm^{-2}$) and lower resistivity (~$10$ $k{\Omega}$) at the Dirac point we observe current flow along the graphene edges. Combined with simulations, our measurements suggest that enhanced edge doping is responsible for this effect. In addition, a device with low charge impurity (~$10^9$ $cm^{-2}$) and higher resistivity (~$100$ $k{\Omega}$) shows subgap states in the bulk, consistent with the absence of shunting by edge currents.

[6]  arXiv:1711.08011 [pdf, other]
Title: Observation of Gapless Dirac Surface States in ZrGeTe
Comments: 20 pages, 7 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci)

The experimental discovery of the topological Dirac semimetal establishes a platform to search for various exotic quantum phases in real materials. ZrSiS-type materials have recently emerged as topological nodal-line semimetals where gapped Dirac-like surface states are observed. Here, we present a systematic angle-resolved photoemission spectroscopy (ARPES) study of ZrGeTe, a nonsymmorphic symmetry protected Dirac semimetal. We observe two Dirac-like gapless surface states at the same $\bar X$ point of the Brillouin zone. Our theoretical analysis and first-principles calculations reveal that these are protected by crystalline symmetry. Hence, ZrGeTe appears as a rare example of a naturally fine tuned system where the interplay between symmorphic and non-symmorphic symmetry leads to rich phenomenology, and thus opens for opportunities to investigate the physics of Dirac semimetallic and topological insulating phases realized in a single material.

[7]  arXiv:1711.08022 [pdf, other]
Title: Properties of the ferroelectric visible light absorbing semiconductors: Sn$_2$P$_2$S$_6$ and Sn$_2$P$_2$Se$_6$
Subjects: Materials Science (cond-mat.mtrl-sci)

Ferroelectrics with suitable band gaps have recently attracted attention as candidate solar absorbing materials for photovoltaics. The inversion symmetry breaking may promote the separation of photo-excited carriers and allow voltages higher than the band gap. However, these effects are not fully understood, in part because of a lack of suitable model systems for studying these effects in detail. Here, we report properties of ferroelectric Sn$_2$P$_2$S$_6$ and Sn$_2$P$_2$Se$_6$ using first principles calculations. Results are given for the electronic structure, carrier pocket shapes, optical absorption and transport. We find indirect band gaps of 2.20 eV and 1.55 eV, respectively, and favorable band structures for carrier transport, including both holes and electrons. Strong absorption is found above the direct gaps of 2.43 eV and 1.76 eV. Thus these compounds may serve as useful model systems for understanding photovoltaic effects in ferroelectric semiconductors.

[8]  arXiv:1711.08027 [pdf, ps, other]
Title: Understanding Quantum Tunneling using Diffusion Monte Carlo Simulations
Comments: 9 pages, 7 figures
Subjects: Statistical Mechanics (cond-mat.stat-mech); Quantum Physics (quant-ph)

In simple ferromagnetic quantum Ising models characterized by an effective double-well energy landscape the characteristic tunneling time of path-integral Monte Carlo (PIMC) simulations has been shown to scale as the incoherent quantum-tunneling time, i.e., as $1/\Delta^2$, where $\Delta$ is the tunneling gap. Since incoherent quantum tunneling is employed by quantum annealers (QAs) to solve optimization problems, this result suggests there is no quantum advantage in using QAs w.r.t. quantum Monte Carlo (QMC) simulations. A counterexample is the recently introduced shamrock model, where topological obstructions cause an exponential slowdown of the PIMC tunneling dynamics with respect to incoherent quantum tunneling, leaving the door open for potential quantum speedup, even for stoquastic models. In this work, we investigate the tunneling time of projective QMC simulations based on the diffusion Monte Carlo (DMC) algorithm without guiding functions, showing that it scales as $1/\Delta$, i.e., even more favorably than the incoherent quantum-tunneling time, both in a simple ferromagnetic system and in the more challenging shamrock model. However a careful comparison between the DMC ground-state energies and the exact solution available for the transverse-field Ising chain points at an exponential scaling of the computational cost required to keep a fixed relative error as the system size increases.

[9]  arXiv:1711.08059 [pdf, other]
Title: Coherent generation of photonic fractional quantum Hall states in a cavity and the search for anyonic quasiparticles
Comments: 11 pages + references, 10 figures. Supplemental Material currently available at this http URL
Subjects: Quantum Gases (cond-mat.quant-gas); Optics (physics.optics)

We present and analyze a protocol in which polaritons in a non-coplanar optical cavity form fractional quantum Hall states. We model the formation of these states and present techniques for subsequently creating anyons and measuring their fractional exchange statistics. In this protocol, we use a rapid adiabatic passage scheme to sequentially add polaritons to the system, such that the system is coherently driven from $n$ to $n+1$-particle Laughlin states. Quasiholes are created by slowly moving local pinning potentials in from outside the cloud. They are braided by dragging the pinning centers around one another, and the resulting phases are measured interferometrically. The most technically challenging issue with implementing our procedure is that maintaining adiabaticity and coherence requires that the two-particle interaction energy $V_0$ is sufficiently large compared to the single-polariton decay rate $\gamma$, $V_0 /\gamma \gg 10 N^2 \ln N$, where $N$ is the number of particles in the target state. Current experiments have $V_0 /\gamma\sim 50$.

[10]  arXiv:1711.08062 [pdf, other]
Title: Coupling magneto-elastic Lagrangians to spin transfer torque sources
Comments: 6 pages, LaTeX2e, 3 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci); High Energy Physics - Lattice (hep-lat)

The consequences of coupling magnetic and elastic degrees of freedom, where spins and deformations are carried by point-like objects subject to local interactions, are studied, theoretically and by detailed numerical simulations. From the constrained Lagrangians we derive consistent equations of motion for the coupled dynamical variables. In order to probe the dynamics of such a system, we consider external perturbations, such as spin transfer torques for the magnetic part, and homogeneous stresses for the elastic part, associated to their corresponding damping. This approach is applied to the study of ultrafast switching processes in anti-ferromagnetic systems, which have recently attracted attention as candidates for anti-ferromagnetic spintronic devices. Our strategy is then checked in simple, but instructive, situations. We carried out numerical experiments to study, in particular, how the magnetostrictive coupling and external stresses affect the nature of the switching processes in a prototype anti-ferromagnetic material.

[11]  arXiv:1711.08073 [pdf, ps, other]
Title: Reentrant Quantum Spin Hall States in Charge Density Wave Phase of Doped Single-Layer Transition Metal Dichalcogenides
Comments: 14 pages, 12 figures
Subjects: Strongly Correlated Electrons (cond-mat.str-el); Materials Science (cond-mat.mtrl-sci)

Using first-principles calculation methods, we reveal a series of phase transitions as a function of electron doping in single-layer 1T$'$-MoTe$_2$ and 1T$'$-WTe$_2$ exhibiting quantum spin Hall (QSH) edge states without doping. As increasing doping, we show that a phonon mediated superconducting phase first realizes and is followed by a charge density wave (CDW) phase with a nonsymmorphic lattice symmetry. The newly found CDW phase exhibits Dirac or Weyl energy bands with a spin-orbit coupling in case of a fractional band filling and re-enters into topological insulating phase with fully filled bands. The robust resurgence of QSH state coexisting with the CDW phase is shown to originate from band inversions induced by the nonsymmorphic lattice distortion through the strong electron-phonon interaction, thus suggesting a realization of various interfacial states between superconducting, density wave and topological states on a two-dimensional crystal only by doping.

[12]  arXiv:1711.08090 [pdf]
Title: Observation of the quantum Hall effect in confined films of the three-dimensional Dirac semimetal Cd3As2
Comments: Accepted, Phys. Rev. Lett
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci)

The magnetotransport properties of epitaxial films of Cd3As2, a paradigm three-dimensional Dirac semimetal, are investigated. We show that an energy gap opens in the bulk electronic states of sufficiently thin films and, at low temperatures, carriers residing in surface states dominate the electrical transport. The carriers in these states are sufficiently mobile to give rise to a quantized Hall effect. The sharp quantization demonstrates surface transport that is virtually free of parasitic bulk conduction and paves the way for novel quantum transport studies in this class of topological materials. Our results also demonstrate that heterostructuring approaches can be used to study and engineer quantum states in topological semimetals.

[13]  arXiv:1711.08099 [pdf, other]
Title: Degree product rule tempers explosive percolation in the absence of global information
Comments: 6 pages, 5 figures, 1 table
Subjects: Statistical Mechanics (cond-mat.stat-mech)

We introduce a guided network growth model, which we call the degree product rule process, that uses solely local information when adding new edges. For small numbers of candidate edges our process gives rise to a second order phase transition, but becomes first order in the limit of global choice. We provide the set of critical exponents required to characterize the nature of this percolation transition. Such a process permits interventions which can delay the onset of percolation while tempering the explosiveness caused by cluster product rule processes.

[14]  arXiv:1711.08109 [pdf]
Title: Scanning tunneling microscopy and spectroscopy of twisted trilayer graphene
Comments: 4 Figures in main text
Subjects: Materials Science (cond-mat.mtrl-sci); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Twist, as a simple and unique degree of freedom, could lead to enormous novel quantum phenomena in bilayer graphene. A small rotation angle introduces low-energy van Hove singularities (VHSs) approaching the Fermi level, which result in unusual correlated states in the bilayer graphene. It is reasonable to expect that the twist could also affect the electronic properties of few-layer graphene dramatically. However, such an issue has remained experimentally elusive. Here, by using scanning tunneling microscopy/spectroscopy (STM/STS), we systematically studied a twisted trilayer graphene (TTG) with two different small twist angles between adjacent layers. Two sets of VHSs originating from the two twist angles were observed in the TTG, indicating that the TTG could be simply regarded as a combination of two different twisted bilayer graphene. By using high-resolution STS, we observed split of the VHSs and directly imaged spatial symmetry breaking of electronic states around the VHSs. These results suggest that electron-electron interactions play an important role in affecting the electronic properties of graphene systems with low-energy VHSs.

[15]  arXiv:1711.08115 [pdf]
Title: Surface plasmon polaritons in the ultraviolet region
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

We study a surface plasmon polariton mode that is strongly confined in the transverse direction and propagates along a periodically nanostructured metal-dielectric interface. We show that the wavelength of this mode is determined by the period of the structure, and may therefore, be orders of magnitude smaller than the wavelength of a plasmon-polariton propagating along a flat surface. This plasmon polariton exists in the frequency region in which the sum of the real parts of the permittivities of the metal and dielectric is positive, a frequency region in which surface plasmon polaritons do not exist on a flat surface. The propagation length of the new mode can reach a several dozen wavelengths. This mode can be observed in materials that are uncommon in plasmonics, such as aluminum or sodium.

[16]  arXiv:1711.08124 [pdf, other]
Title: Magnetoelectric memory function with optical readout
Comments: 6 pages, 4 figures + Supplementary (10 pages and 4 figures)
Subjects: Strongly Correlated Electrons (cond-mat.str-el)

The ultimate goal of multiferroic research is the development of new-generation non-volatile memory devices, the so-called magnetoelectric (ME) memories, where magnetic bits are controlled via electric fields without the application of electrical currents subject to dissipation. This low-power operation exploits the entanglement of the magnetization and the electric polarization coexisting in multiferroic materials. Here we demonstrate the optical readout of ME memory states in the antiferromagnetic (AFM) and antiferroelectric (AFE) LiCoPO$_4$, based on the strong absorption difference of THz radiation between its two types of ME domains. This unusual contrast is attributed to the dynamic ME effect of the spin-wave excitations, as confirmed by our microscopic model, which also captures the characteristics of the observed static ME effect. Our proof-of-principle study, demonstrating the control and the optical readout of ME domains in LiCoPO$_4$, lays down the foundation for future ME memory devices based on antiferroelectric-antiferromagnetic insulators.

[17]  arXiv:1711.08133 [pdf, ps, other]
Title: Coincidence of magnetic and valence quantum critical points in CeRhIn5 under pressure
Comments: 6 pages, 6 figures, to appear in PRB
Subjects: Superconductivity (cond-mat.supr-con)

We present accurate electrical resistivity measurements along the two principle crystallographic axes of the pressure-induced heavy-fermion superconductor CeRhIn5 up to 5.63 GPa. For both directions, a valence crossover line is identified in the p-T plane and the extrapolation of this line to zero temperature coincides with the collapse of the magnetic ordering temperature. Furthermore, it is found that the p-T phase diagram of CeRhIn5 in the valence crossover region is very similar to that of CeCu2Si2. These results point to the essential role of Ce-4f electron delocalization in both destroying magnetic order and realizing superconductivity in CeRhIn5 under pressure.

[18]  arXiv:1711.08148 [pdf]
Title: Microstructural analysis and optical properties of Cs2BiAgBr6 halide double perovskite single crystals
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci)

Single crystals of Cs2BiAgBr6 lead-free perovskite were grown by crystallization from supersaturated solution. According to characterization by XRD and EBSD methods the double perovskite single crystal are of the cubic Fm-3m symmetry with the lattice constant a = 11.20 {\AA}. DFT predictions based on the single crystal X-ray diffraction analysis reveal that the material is an indirect band gap semiconductor. Low temperature (1.4 K) photoluminescence spectra demonstrate three broadened bands that correspond to two lowest computed indirect and one direct band-to-band transitions.

[19]  arXiv:1711.08164 [pdf, ps, other]
Title: The valley filter efficiency of monolayer graphene and bilayer graphene line defect model
Comments: 6 figures
Journal-ref: New J. Phys. 18 (2016) 103024
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

In addition to electron charge and spin, novel materials host another degree of freedom, the valley. For a junction composed of valley filter sandwiched by two normal terminals, we focus on the valley efficiency under disorder with two valley filter models based on monolayer and bilayer graphene. Applying the transfer matrix method, valley resolved transmission coefficients are obtained. We find that: i) under weak disorder, when the line defect length is over about $15\rm nm$, it functions as a perfect channel (quantized conductance) and valley filter (totally polarized); ii) in the diffusive regime, combination effects of backscattering and bulk states assisted intervalley transmission enhance the conductance and suppress the valley polarization; iii) for very long line defect, though the conductance is small, polarization is indifferent to length. Under perpendicular magnetics field, the characters of charge and valley transport are only slightly affected. Finally we discuss the efficiency of transport valley polarized current in a hybrid system.

[20]  arXiv:1711.08168 [pdf, ps, other]
Title: Perfect valley filter based on topological phase in disordered $\rm{Sb}$ Monolayer Heterostructure
Comments: 5 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

The hydrogenated $\rm{Sb}$ monolayer epitaxially grown on a $\rm{LaFeO_3}$ substrate is a novel type of two-dimensional material hosting quantum spin-quantum anomalous Hall (QS-QAH) states. For a device formed by $\rm{Sb}$ monolayer ribbon, the QAH edge states, belong to a single valley, are located at opposite edges of the ribbon. The QSH edge states, on the other hand, belong to the other valley and are distributed in a very narrow region at the same edge. In this paper, we find such material can be used to fabricate perfect valley filter. Adopting scattering matrix method and Green's function method, the valley resolved transport and spatial distribution of local current are calculated, in the present of Anderson disorder, edge defects and edge deformations. The numerical results demonstrate that, in the presence of above three types of disorder with moderate strength, the carriers can flow disspationless with nearly perfect valley polarization. Moreover, when the device becomes longer, the transport current does not decrease while the valley filter works even better. The origin is that the disorder can destroy the QSH edge states, but the valley-polarized QAH edge states can well hold.

[21]  arXiv:1711.08177 [pdf, other]
Title: Interband absorption edge in topological insulators Bi$_2$(Te$_{1-x}$Se$_x$)$_3$
Comments: 9 figures
Subjects: Materials Science (cond-mat.mtrl-sci)

We have investigated the optical properties of thin films of topological insulators Bi$_{2}$Te$_{3}$, Bi$_{2}$Se$_{3}$ and their alloys Bi$_2$(Te$_{1-x}$Se$_x$)$_3$ on BaF$_{2}$ substrates by a combination of infrared ellipsometry and reflectivity in the energy range from 0.06 to 6.5 eV. For the onset of interband absorption in Bi$_2$Se$_3$, after the correction for the Burstein-Moss effect, we find the value of direct bandgap of $215\pm10$ meV at 10 K. Our data supports the picture that Bi$_2$Se$_3$ has a direct band gap located at the $\Gamma$ point in the Brillouin zone and that the valence band reaches up to the Dirac point and has the shape of a downward oriented paraboloid, i.e. without a camel-back structure. In Bi$_2$Te$_3$, the onset of strong direct interband absorption at 10 K is at a similar energy of about 200 meV, with a weaker additional feature at about 170 meV. Our data support the recent GW band structure calculations suggesting that the direct interband transition does not occur at the $\Gamma$ point but near the Z-F line of the Brillouin zone. In the Bi$_2$(Te$_{1-x}$Se$_x$)$_3$ alloy, the energy of the onset of direct interband transitions exhibits a maximum near $x=0.3$ (i.e. the composition of Bi$_2$Te$_2$Se), suggesting that the crossover of the direct interband transitions between the two points in the Brillouin zone occurs close to this composition.

[22]  arXiv:1711.08204 [pdf, other]
Title: Phase diagram for the Harper model of the honeycomb lattice
Comments: 8 pages, 12 figures
Subjects: Strongly Correlated Electrons (cond-mat.str-el); Disordered Systems and Neural Networks (cond-mat.dis-nn); Statistical Mechanics (cond-mat.stat-mech)

The Harper equation arising out of a tight-binding model of electrons on a honeycomb lattice subject to a uniform magnetic field perpendicular to the plane is studied. Contrasting and complementary approaches involving von Neumann entropy, fidelity, fidelity susceptibility, multifractal analysis are employed to characterize the phase diagram. The phase diagram consists of three phases: two metallic phases and an insulating phase. A variant model where next nearest neighbor hopping is included, exhibits a mobility edge and does not allow for a simple single phase diagram characterizing all the eigenstates.

[23]  arXiv:1711.08242 [pdf, other]
Title: Filamentous phages as building blocks for reconfigurable and hierarchical self-assembly
Authors: Thomas Gibaud
Journal-ref: Journal of Physics: Condensed Matter 29, 493003 (2017)
Subjects: Soft Condensed Matter (cond-mat.soft); Biological Physics (physics.bio-ph)

Filamentous bacteriophages such as fd-like viruses are monodisperse rod-like colloids that have well defined properties: diameter, length, rigidity, charge and chirality. Engineering those viruses leads to a library of colloidal rods which can be used as building blocks for reconfigurable and hierarchical self-assembly. Their condensation in aqueous solution \th{with additive polymers which act as depletants to induce} attraction between the rods leads to a myriad of fluid-like micronic structures ranging from isotropic/nematic droplets, colloid membranes, achiral membrane seeds, twisted ribbons, $\pi$-wall, pores, colloidal skyrmions, M\"obius anchors, scallop membranes to membrane rafts. Those structures and the way they shape shift not only shed light on the role of entropy, chiral frustration and topology in soft matter but it also mimics many structures encountered in different fields of science. On one hand, filamentous phages being an experimental realization of colloidal hard rods, their condensation mediated by depletion interactions constitutes a blueprint for self-assembly of rod-like particles and provides fundamental foundation for bio- or material oriented applications. On the other hand, the chiral properties of the viruses restrict the generalities of some results but vastly broaden the self-assembly possibilities.

[24]  arXiv:1711.08246 [pdf, ps, other]
Title: Turbulent statistics and intermittency enhancement in coflowing superfluid $^4$He
Comments: 12 pages, 7 figures
Subjects: Other Condensed Matter (cond-mat.other)

The large scale turbulent statistics of mechanically driven superfluid $^4$He was shown experimentally to follow the classical counterpart. In this paper we use direct numerical simulations to study the whole range of scales in a range of temperatures $T \in[1.3,2.1]$K. The numerics employ self-consistent and non-linearly coupled normal and superfluid components. The main results are that (i) the velocity fluctuations of normal and super components are well-correlated in the inertial range of scales, but decorrelate at small scales. (ii) The energy transfer by mutual friction between components is particularly efficient in the temperature range between 1.8K and 2K, leading to enhancement of small scales intermittency for these temperatures. (iii) At low $T$ and close to $T_{\lambda}$ the scaling properties of the energy spectra and structure functions of the two components are approaching those of classical hydrodynamic turbulence.

[25]  arXiv:1711.08250 [pdf, other]
Title: A general algorithm for computing bound states in infinite tight-binding systems
Comments: 21 pages, 13 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

We propose a robust and efficient algorithm for computing bound states of infinite tight-binding systems that are made up of a finite scattering region connected to semi-infinite leads. Our method uses wave matching in close analogy to the approaches used to obtain propagating states and scattering matrices. We show that our algorithm is robust in presence of slowly decaying bound states where a diagonalization of a finite system would fail. It also allows to calculate the bound states that can be present in the middle of a continuous spectrum. We apply our technique to quantum billiards and the following topological materials: Majorana states in 1D superconducting nanowires, edge states in the 2D quantum spin Hall phase, and Fermi arcs in 3D Weyl semimetals.

[26]  arXiv:1711.08259 [pdf, ps, other]
Title: Dynamics of quantum collapse in coupled quantum dots
Authors: H. Cruz
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)

In this letter, we have considered an electron in a coupled quantum dot system interacting with a detector represented by a point contact. We present a dynamical model for wave function collapse in the strong coupling to the detector limit. In our model, the electron in the double quantum dot makes a fast transition minimizing the emission of electromagnetic radiation. In this way, a principle of leats emitted radiation can provide a possible description of wave function collapse.

[27]  arXiv:1711.08284 [pdf, other]
Title: Optimization of ohmic contacts to n-type GaAs nanowires
Comments: 10 pages, 9 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

III-V nanowires are comprehensively studied because of their suitability for optoelectronic quantum technology applications. However, their small dimensions and the spatial separation of carriers from the wire surface render electrical contacting difficult. Systematically studying ohmic contact formation by diffusion to $n$-doped GaAs nanowires, we provide a set of optimal annealing parameters for Pd/Ge/Au ohmic contacts. We reproducibly achieve low specific contact resistances of $\sim2\times10^{-7}\,\Omega\text{cm}^2$ at room temperature becoming an order of magnitude higher at $T\simeq4.2\,$K. We provide a phenomenological model to describe contact resistances as a function of diffusion parameters. Implementing a transfer-matrix method, we numerically study the influence of the Schottky barrier on the contact resistance. Our results indicate that contact resistances can be predicted using various barrier shapes but further insights into structural properties would require a full microscopic understanding of the complex diffusion processes.

[28]  arXiv:1711.08294 [pdf, other]
Title: Observation of A$_g^1$ Raman mode splitting in few layers black phosphorus encapsulated with hexagonal boron nitride
Comments: 15 pages, 4 figures just accepted for publication in Nanoscale this http URL
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

We investigate the impact of the encapsulation with hexagonal boron nitride (h-BN) on the Raman spectrum of few layer black phosphorus. The encapsulation results in a significant reduction of the line width of the Raman modes of black phosphorus, due to a reduced phonon scattering rate. We observe a so far elusive peak in the Raman spectra $\sim$4cm$^{-1}$ above the A$_{\text{g}}^1$ mode in trilayer and thicker flakes, which had not been observed experimentally. The newly observed mode originates from the strong black phosphorus inter-layer interaction, which induces a hardening of the surface atoms vibration with respect to the corresponding modes of the inner layers. The observation of this mode suggests a significant impact of h-BN encapsulation on the properties of black phosphorus and can serve as an indicator of the quality of its surface.

[29]  arXiv:1711.08300 [pdf]
Title: Coexistence of strongly buckled germanene phases on Al(111)
Comments: 8 pages, 4 figures, 1 support information
Journal-ref: Beilstein J. Nanotechnol.8,1946,2017
Subjects: Materials Science (cond-mat.mtrl-sci)

We report a study of structural and electronic properties of a germanium layer on Al(111) using scanning tunneling microscopy (STM), low energy electron diffraction and core-level photoelectron spectroscopy. Experimental results show that a germanium layer can be formed at a relatively high substrate temperature showing either (3$\times$3) or ($\sqrt{7}$$\times$$\sqrt{7}$)R$\pm$19.1{\deg} reconstructions. First-principles calculations based on density functional theory suggest an atomic model consisting of a strongly buckled (2$\times$2) germanene layer, which is stable in two different orientations on Al(111). Simulated STM of both orientations fit nicely with experimental STM images and the Ge 3d core-level data decomposed into four components is consistent with the suggested model.

[30]  arXiv:1711.08303 [pdf, ps, other]
Title: Constraining Forces Stabilizing Superconductivity in Bismuth
Authors: Ekkehard Krüger
Subjects: Superconductivity (cond-mat.supr-con); Strongly Correlated Electrons (cond-mat.str-el)

As shown in former papers, the nonadiabatic Heisenberg model presents a novel mechanism of Cooper pair formation generated by the strongly correlated atomic-like motion of the electrons in narrow, roughly half-filled "superconducting bands". These are energy bands represented by optimally localized spin-dependent Wannier functions adapted to the symmetry of the material under consideration. The formation of Cooper pairs is not the result of an attractive electron-electron interaction but can be described in terms of quantum mechanical constraining forces constraining the electrons to form Cooper pairs. There is theoretical and experimental evidence that only this nonadiabatic mechanism operating in superconducting bands may produce eigenstates in which the electrons form Cooper pairs. These constraining forces stabilize the Cooper pairs in any superconductor, whether conventional or unconventional. Here we report evidence that also the experimentally found superconducting state in bismuth at ambient as well as at high pressure is connected with a narrow, roughly half-filled superconducting band in the respective band structure. This observation corroborates once more the significance of constraining forces in the theory of superconductivity.

[31]  arXiv:1711.08308 [pdf, other]
Title: Curvature by design and on demand in liquid crystal elastomers
Subjects: Soft Condensed Matter (cond-mat.soft)

The shape of liquid crystalline elastomers (LCEs) with spatial variation in the director orientation can be transformed by exposure to a stimulus. Here, informed by previously reported analytical treatments, we prepare complex spiral patterns imprinted into LCEs and quantify the resulting shape transformation. Quantification of the stimuli-induced shapes reveals good agreement between predicted and experimentally observed curvatures. We conclude this communication by reporting a design strategy to allow LCE films to be anchored at their external boundaries onto rigid substrates without incurring internal, mechanical-mismatch stresses upon actuation, a critical advance to the realization of shape transformation of LCEs in practical device applications.

[32]  arXiv:1711.08316 [pdf]
Title: Distribution of size particles in the Gibbs system
Authors: V. V. Ryazanov
Comments: 16 pages, in Russian, 2 figures
Subjects: Statistical Mechanics (cond-mat.stat-mech); Chemical Physics (physics.chem-ph)

In the framework of the Gibbs statistical theory, the question of the size of the particles forming the statistical system is investigated. This task is relevant for a wide variety of applications. The distribution for particle sizes and the moments of this quantity are determined from probabilistic considerations. The results are compared with different models and approximations. The particle size depends on the interactions in the system, on the compressibility factor, on the number of interacting particles. The cases of the absence and presence of a rigid incompressible particle core are considered.

[33]  arXiv:1711.08342 [pdf, other]
Title: Laser induced THz emission from femtosecond photocurrents in Co/ZnO/Pt and Co/Cu/Pt multilayers
Comments: 15 pages, 6 figures, 2 tables
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

The ultrashort laser excitation of Co/Pt magnetic heterostructures can effectively generate spin and charge currents at the interfaces between magnetic and nonmagnetic layers. The direction of these photocurrents can be controlled by the helicity of the circularly polarized laser light and an external magnetic field. Here, we employ THz time-domain spectroscopy to investigate further the role of interfaces in these photo-galvanic phenomena. In particular, the effects of either Cu or ZnO interlayers on the photocurrents in Co/X/Pt (X = Cu, ZnO) have been studied by varying the thickness of the interlayers up to 5 nm. The results are discussed in terms of spin-diffusion phenomena and interfacial spin-orbit torque.

[34]  arXiv:1711.08366 [pdf, other]
Title: Topological Hall effect from strong to weak coupling
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Topological Hall effect (THE) of electrons coupled to a noncoplanar spin texture has been studied so far for the strong- and weak-coupling regimes separately; the former in terms of the Berry phase and the latter by perturbation theory. In this letter, we present a unified treatment in terms of spin gauge field by considering not only the adiabatic (Berry phase) component of the gauge field but also the nonadiabatic component. While only the adiabatic contribution is important in the strong-coupling regime, it is completely canceled by a part of the nonadiabatic contribution in the weak-coupling regime, where the THE is governed by the rest of the nonadiabatic terms. We found a new weak-coupling region that cannot be accessed by a simple perturbation theory, where the Hall conductivity is proportional to M, with 2M being the exchange splitting of the electron spectrum.

[35]  arXiv:1711.08373 [pdf, other]
Title: Chemical continuous time random walks
Comments: 12 pages, 2 figures
Subjects: Statistical Mechanics (cond-mat.stat-mech)

Kinetic Monte Carlo methods such as the Gillespie algorithm model chemical reactions as random walks in particle number space. The inter-reaction times are exponentially distributed under the assumption that the system is well mixed. We introduce an arbitrary inter-reaction time distribution, which may account for the impact of incomplete mixing on chemical reactions, and in general stochastic reaction delay, which may represent the impact of extrinsic noise. This process defines an inhomogeneous continuous time random walk in particle number space, from which we derive a generalized chemical master equation. This leads naturally to a generalization of the Gillespie algorithm. Based on this formalism, we determine the modified chemical rate laws for different inter-reaction time distributions. This framework traces Michaelis--Menten-type kinetics back to finite-mean delay times, and predicts time-nonlocal macroscopic reaction kinetics as a consequence of broadly distributed delays. Non-Markovian kinetics exhibit weak ergodicity breaking and show key features of reactions under local non-equilibrium.

[36]  arXiv:1711.08375 [pdf, other]
Title: Irreversible Markov chains in spin models: Topological excitations
Authors: Ze Lei, Werner Krauth
Comments: 5 pages, 5 figures
Subjects: Statistical Mechanics (cond-mat.stat-mech)

We analyze the convergence of the irreversible event-chain Monte Carlo algorithm for continuous spin models in the presence of topological excitations. In the two-dimensional XY model, we show that the local nature of the Markov-chain dynamics leads to slow decay of vortex-antivortex correlations while spin waves decorrelate very quickly. Using a Frechet description of the maximum vortex-antivortex distance, we quantify the contributions of topological excitations to the equilibrium correlations, and show that they vary from a dynamical critical exponent z \sim 2 at the critical temperature to z \sim 0 in the limit of zero temperature. We confirm the event-chain algorithm's fast relaxation (corresponding to z = 0) of spin waves in the harmonic approximation to the XY model. Mixing times (describing the approach towards equilibrium from the least favorable initial state) however remain much larger than equilibrium correlation times at low temperatures. We also describe the respective influence of topological monopole-antimonopole excitations and of spin waves on the event-chain dynamics in the three-dimensional Heisenberg model.

[37]  arXiv:1711.08385 [pdf, other]
Title: Mesoscopic Modelling and Simulation of Soft Matter
Comments: 16 pages, 6 figures
Journal-ref: Soft Matter, 2017
Subjects: Soft Condensed Matter (cond-mat.soft); Computational Physics (physics.comp-ph)

The deformability of soft condensed matter often requires modelling of hydrodynamical aspects to gain quantitative understanding. This, however, requires specialised methods that can resolve the multiscale nature of soft matter systems. We review a number of the most popular simulation methods that have emerged, such as Langevin dynamics, dissipative particle dynamics, multi-particle collision dynamics, sometimes also referred to as stochastic rotation dynamics, and the lattice-Boltzmann method. We conclude this review with a short glance at current compute architectures for high-performance computing and community codes for soft matter simulation.

[38]  arXiv:1711.08388 [pdf, ps, other]
Title: Effect of Image Potential on Spin Polarized Transport through Magnetic Tunnel Junctions
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

We study the effect of image potential on spin polarized transport through Fe/MgO/Fe magnetic tunnel junctions in the presence of symmetry filtering. The image potential is included within the Simmon's model coupled with the non-equilibrium Green's function formalism to calculate the quantum transport. The increase in the current densities for the $\Delta_1$ symmetry and the $\Delta_5$ symmetry bands due to the image potential is more pronounced at higher bias, whereas, the increase in the magnitude of the tunnel magnetoresistance ratio is more prominent at lower bias for various barrier thicknesses.

[39]  arXiv:1711.08397 [pdf]
Title: Thermoelectric power factor of nanocomposite materials from two-dimensional quantum transport simulations
Comments: 33 pages, 10 figures
Journal-ref: Phys. Rev. B 96, 195425, 2017
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

Nanocomposites are promising candidates for the next generation of thermoelectric materials since they exhibit extremely low thermal conductivities as a result of phonon scattering on the boundaries of the various material phases. The nanoinclusions, however, should not degrade the thermoelectric power factor, and ideally should increase it, so that benefits to the ZT figure of merit can be achieved. In this work we employ the Non-Equilibrium Greens Function (NEGF) quantum transport method to calculate the electronic and thermoelectric coefficients of materials embedded with nanoinclusions. For computational effectiveness we consider two-dimensional nanoribbon geometries, however, the method includes the details of geometry, electron-phonon interactions, quantisation, tunneling, and the ballistic to diffusive nature of transport, all combined in a unified approach. This makes it a convenient and accurate way to understand electronic and thermoelectric transport in nanomaterials, beyond semiclassical approximations, and beyond approximations that deal with the complexities of the geometry. We show that the presence of nanoinclusions within a matrix material offers opportunities for only weak energy filtering, significantly lower in comparison to superlattices, and thus only moderate power factor improvements. However, we describe how such nanocomposites can be optimised to limit degradation in the thermoelectric power factor and elaborate on the conditions that achieve the aforementioned mild improvements. Importantly, we show that under certain conditions, the power factor is independent of the density of nanoinclusions, meaning that materials with large nanoinclusion densities which provide very low thermal conductivities, can also retain large power factors and result in large ZT figures of merit.

[40]  arXiv:1711.08401 [pdf]
Title: Reaction paths of alane dissociation on the Si(001) surface
Comments: 19 pages, 8 figures, submitted to J. Physics.: Condens. Matter
Subjects: Materials Science (cond-mat.mtrl-sci)

Building on our earlier study, we examine the kinetic barriers to decomposition of alane, AlH$_3$, on the Si(001) surface, using the nudged elastic band (NEB) approach within DFT. We find that the initial decomposition to AlH with two H atoms on the surface proceeds without a significant barrier. There are several pathways available to lose the final hydrogen, though these present barriers of up to 1 eV. Incorporation is more challenging, with the initial structures less stable in several cases than the starting structures, just as was found for phosphorus. We identify a stable route for Al incorporation following selective surface hydrogen desorption (e.g. by STM tip). The overall process parallels PH$_3$, and indicates that atomically precise acceptor doping should be possible.

[41]  arXiv:1711.08402 [pdf, other]
Title: Filling the holes in the CaFe$_{4}$As$_{3}$ structure: synthesis and magnetism of CaCo$_{5}$As$_{3}$
Subjects: Strongly Correlated Electrons (cond-mat.str-el)

Here we investigate single crystals of CaCo$_{5}$As$_{3}$ by means of single crystal X-ray diffraction, microprobe, magnetic susceptibility, heat capacity, and pressure-dependent transport measurements. CaCo$_{5}$As$_{3}$ shares the same structure of CaFe$_{4}$As$_{3}$ with an additional Co atom filling a lattice vacancy and undergoes a magnetic transition at $T_{M} = 16$ K associated with a frustrated magnetic order. CaCo$_{5}$As$_{3}$ displays metallic behavior and its Sommerfeld coefficient ($\gamma = 70$ mJ/mol.K$^{2}$) indicates a moderate enhancement of electron-electron correlations. Transport data under pressures to $2.5$ GPa reveal a suppression of $T_{M}$ at a rate of $-0.008$ K/GPa. First-principle electronic structure calculations show a complex 3D band structure and magnetic moments that depend on the local environment at each Co site. Our results are compared with previous data on CaFe$_{4}$As$_{3}$ and provide a scenario for a magnetically frustrated ground state in this family of compounds.

[42]  arXiv:1711.08428 [pdf, other]
Title: Computing return times or return periods with rare event algorithms
Subjects: Statistical Mechanics (cond-mat.stat-mech); Computational Physics (physics.comp-ph); Data Analysis, Statistics and Probability (physics.data-an)

The average time between two occurrences of the same event, referred to as its return time (or return period), is a useful statistical concept for practical applications. For instance insurances or public agency may be interested by the return time of a 10m flood of the Seine river in Paris. However, due to their scarcity, reliably estimating return times for rare events is very difficult using either observational data or direct numerical simulations. For rare events, an estimator for return times can be built from the extrema of the observable on trajectory blocks. Here, we show that this estimator can be improved to remain accurate for return times of the order of the block size. More importantly, we show that this approach can be generalised to estimate return times from numerical algorithms specifically designed to sample rare events. So far those algorithms often compute probabilities, rather than return times. The approach we propose provides a computationally extremely efficient way to estimate numerically the return times of rare events for a dynamical system, gaining several orders of magnitude of computational costs. We illustrate the method on two kinds of observables, instantaneous and time-averaged, using two different rare event algorithms, for a simple stochastic process, the Ornstein-Uhlenbeck process. As an example of realistic applications to complex systems, we finally discuss extreme values of the drag on an object in a turbulent flow.

[43]  arXiv:1711.08455 [pdf, other]
Title: Frustration and quantum criticality
Authors: Matthias Vojta
Comments: 25 pages, 8 figs; mini-review prepared for Rep. Prog. Phys.; comments welcome
Subjects: Strongly Correlated Electrons (cond-mat.str-el); Statistical Mechanics (cond-mat.stat-mech)

This review article is devoted to the interplay between frustrated magnetism and quantum critical phenomena, covering both theoretical concepts and ideas as well as recent experimental developments in correlated-electron materials. The first part deals with local-moment magnetism in Mott insulators and the second part with frustration in metallic systems. In both cases, frustration can either induce exotic phases accompanied by exotic quantum critical points or lead to conventional ordering with unconventional crossover phenomena. In addition, the competition of multiple phases inherent to frustrated systems can lead to multi-criticality.

Cross-lists for Thu, 23 Nov 17

[44]  arXiv:1711.07903 (cross-list from hep-th) [pdf, other]
Title: Diffusion in higher dimensional SYK model with complex fermions
Subjects: High Energy Physics - Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); General Relativity and Quantum Cosmology (gr-qc)

We construct a new higher dimensional SYK model with complex fermions on bipartite lattices. As an extension of the original zero-dimensional SYK model, we focus on the one-dimension case, and similar Hamiltonian can be obtained in higher dimensions. This model has a conserved U(1) fermion number Q and a conjugate chemical potential \mu. We evaluate the thermal and charge diffusion constants via large q expansion at low temperature limit. The results show that the diffusivity depends on the ratio of free Majorana fermions to Majorana fermions with SYK interactions. The transport properties and the butterfly velocity are accordingly calculated at low temperature. The thermal conductivity is proportional to the temperature.

[45]  arXiv:1711.07982 (cross-list from quant-ph) [pdf, other]
Title: Symmetry-enriched topological order in tensor networks: Defects, gauging and anyon condensation
Comments: 76 + 2 pages, many figures, many tables, comments welcome
Subjects: Quantum Physics (quant-ph); Strongly Correlated Electrons (cond-mat.str-el)

We study symmetry-enriched topological order in two-dimensional tensor network states by using graded matrix product operator algebras to represent symmetry induced domain walls. A close connection to the theory of graded unitary fusion categories is established. Tensor network representations of the topological defect superselection sectors are constructed for all domain walls. The emergent symmetry-enriched topological order is extracted from these representations, including the symmetry action on the underlying anyons. Dual phase transitions, induced by gauging a global symmetry, and condensation of a bosonic subtheory, are analyzed and the relationship between topological orders on either side of the transition is derived. Several examples are worked through explicitly.

[46]  arXiv:1711.08252 (cross-list from nlin.CG) [pdf, other]
Title: Effect of self-deflection on a totally asymmetric simple exclusion process with functions of site-assignments
Subjects: Cellular Automata and Lattice Gases (nlin.CG); Statistical Mechanics (cond-mat.stat-mech); Physics and Society (physics.soc-ph)

This study proposes a model of a totally asymmetric simple exclusion process on a single channel lane with functions of site-assignments along the pitlane. The system model attempts to insert a new particle to the leftmost site at a certain probability by randomly selecting one of the empty sites in the pitlane, and reserving it for the particle. Thereafter, the particle is directed to stop at the site only once during its travel. Recently, the system was determined to show a self-deflection effect, in which the site usage distribution biases spontaneously toward the leftmost site, and the throughput becomes maximum when the site usage distribution is slightly biased to the rightmost site, instead of being an exact uniform distribution. Our exact analysis describes this deflection effect and show a good agreement with simulations.

[47]  arXiv:1711.08432 (cross-list from math.PR) [pdf, ps, other]
Title: Fluctuation exponents for stationary exactly solvable lattice polymer models via a Mellin transform framework
Comments: 33 pages, 8 figures
Subjects: Probability (math.PR); Statistical Mechanics (cond-mat.stat-mech)

We develop a Mellin transform framework which allows us to simultaneously analyze the four known exactly solvable 1+1 dimensional lattice polymer models: the log-gamma, strict-weak, beta, and inverse-beta models. Using this framework we prove the conjectured fluctuation exponents of the free energy and the polymer path for the stationary point-to-point versions of these four models. The fluctuation exponent for the polymer path was previously unproved for the strict-weak, beta, and inverse-beta models.

[48]  arXiv:1711.08450 (cross-list from hep-th) [pdf, other]
Title: Magnetoydroynamics with chiral anomaly: phases of collective excitations and instabilities
Comments: 8 pages, 3 figures
Subjects: High Energy Physics - Theory (hep-th); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)

We study the relativistic hydrodynamics with chiral anomaly and dynamical electromagnetic fields, Chiral MagnetoHydroDynamics (CMHD). We formulate the CMHD as a low-energy effective theory based on a derivative expansion. We demonstrate the modification of ordinary MagnetoHydroDynamics (MHD) due to chiral anomaly can be obtained from the second law of thermodynamics and is tied to chiral magnetic effect with the universal coefficient. When axial charge imbalance becomes larger than a critical value, a new type of collective gapless excitation in the CMHD appears, as a result of the interplay among magnetic field, flow velocity, and chiral anomaly; we call it "Chiral MagnetoHelical Mode" (CMHM). These modes carry definite magnetic and fluid helicities and will either grow exponentially or dissipate in time, depending on the relative sign between their helicity and axial charge density. The presence of exponentially growing CMHM indicates a hydrodynamic instability.

Replacements for Thu, 23 Nov 17

[49]  arXiv:1609.02064 (replaced) [pdf, other]
Title: Percolation phenomena inside films composed of long flexible macromolecules
Comments: 15 pages, 6 figures
Subjects: Soft Condensed Matter (cond-mat.soft); Statistical Mechanics (cond-mat.stat-mech)
[50]  arXiv:1609.06528 (replaced) [pdf, other]
Title: Quantum model for mode locking in pulsed semiconductor quantum dots
Comments: 20.1 pages, including appendices; 7 figures; with Erratum and corrected Figs. 2 and 3
Journal-ref: Phys. Rev. B 94, 245308 (2016); Erratum: Phys. Rev. B 96, 199904 (2017)
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)
[51]  arXiv:1609.09060 (replaced) [pdf, other]
Title: Machine Learning Topological States
Comments: 12 pages, 7 figures, accepted for publication in Phys. Rev. B
Journal-ref: Phys. Rev. B 96, 195145 (2017)
Subjects: Disordered Systems and Neural Networks (cond-mat.dis-nn); Statistical Mechanics (cond-mat.stat-mech); Strongly Correlated Electrons (cond-mat.str-el); Quantum Physics (quant-ph)
[52]  arXiv:1701.00022 (replaced) [pdf, other]
Title: High-temperature charge density wave correlations in La$_{1.875}$Ba$_{0.125}$CuO$_{4}$ without spin-charge locking
Comments: Accepted in Proceeding of the National Academy of Sciences; 8 pages, 4 figures
Journal-ref: H. Miao et al., PNAS 114, 12430-12435 (2017)
Subjects: Superconductivity (cond-mat.supr-con); Strongly Correlated Electrons (cond-mat.str-el)
[53]  arXiv:1701.00116 (replaced) [pdf, other]
Title: A rigourous demonstration of the validity of Boltzmann's scenario for the spatial homogenization of a freely expanding gas and the equilibration of the Kac ring
Journal-ref: J Stat Phys (2017) 168: 772
Subjects: Mathematical Physics (math-ph); Statistical Mechanics (cond-mat.stat-mech)
[54]  arXiv:1704.04973 (replaced) [pdf, other]
Title: Partition function zeros of the p-state clock model in the complex temperature plane
Authors: Dong-Hee Kim
Journal-ref: Phys. Rev. E 96, 052130 (2017)
Subjects: Statistical Mechanics (cond-mat.stat-mech)
[55]  arXiv:1704.05965 (replaced) [pdf]
Title: Realization of room-temperature ferromagnetic semiconducting state in graphene monolayer
Comments: 4 Figures in main text
Subjects: Materials Science (cond-mat.mtrl-sci); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[56]  arXiv:1705.05982 (replaced) [pdf, ps, other]
Title: Understanding Quality Factor Degradation in Superconducting Niobium Cavities at Low Microwave Field Amplitudes
Comments: final version
Subjects: Accelerator Physics (physics.acc-ph); Superconductivity (cond-mat.supr-con); Quantum Physics (quant-ph)
[57]  arXiv:1705.06901 (replaced) [pdf, other]
Title: Topological networks for quantum communication between distant qubits
Comments: 11 pages, 7 figures; supplement: 27 pages, 9 figures; updated to published version
Journal-ref: npj Quantum Information 3, 47 (2017)
Subjects: Quantum Physics (quant-ph); Other Condensed Matter (cond-mat.other)
[58]  arXiv:1706.02539 (replaced) [pdf]
Title: Scale-invariant large nonlocality in polycrystalline graphene
Comments: Main paper (14 pages, 5 figures) and Supplementary information (8 pages, 8 figures)
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[59]  arXiv:1706.04793 (replaced) [pdf, other]
Title: Husimi function and phase-space analysis of bilayer quantum Hall systems at $ν=2/λ$
Comments: 13 pages, 6 figures. New section added. Novel results and insights further highlighted
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)
[60]  arXiv:1706.09543 (replaced) [pdf, ps, other]
Title: Absence of replica symmetry breaking in the transverse and longitudinal random field Ising model
Authors: C. Itoi
Comments: 17 pages
Subjects: Mathematical Physics (math-ph); Disordered Systems and Neural Networks (cond-mat.dis-nn); Quantum Physics (quant-ph)
[61]  arXiv:1707.03765 (replaced) [pdf, other]
Title: Computing Singularly Perturbed Differential Equations
Comments: This paper has appeared in Journal of Computational Physics, Volume 354 (pages 417-446)
Journal-ref: Journal of Computational Physics 354 (2018) 417-446
Subjects: Numerical Analysis (math.NA); Materials Science (cond-mat.mtrl-sci); Computational Physics (physics.comp-ph)
[62]  arXiv:1707.04307 (replaced) [pdf, other]
Title: Clock spectroscopy of interacting bosons in deep optical lattices
Journal-ref: New J. Phys. 19 113006 (2017)
Subjects: Quantum Gases (cond-mat.quant-gas)
[63]  arXiv:1707.05025 (replaced) [pdf, other]
Title: Observation of Open-Orbit Fermi Surface Topology in Extremely Large Magnetoresistance Semimetal MoAs$_2$
Comments: 6 pages, 4 figures
Subjects: Materials Science (cond-mat.mtrl-sci); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Strongly Correlated Electrons (cond-mat.str-el)
[64]  arXiv:1707.05117 (replaced) [pdf, other]
Title: Majorana splitting from critical currents in Josephson junctions
Comments: 10 pages, 10 figures. Published version
Journal-ref: Phys. Rev. B 96, 205425 (2017)
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[65]  arXiv:1707.05578 (replaced) [pdf, other]
Title: Signature of tilted Dirac cones in Weiss oscillations of $8-Pmmn$ borophene
Comments: To appear in Physical Review B
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[66]  arXiv:1708.00751 (replaced) [pdf, other]
Title: Non-equilibrium 2D Ising model with stationary uphill diffusion
Subjects: Statistical Mechanics (cond-mat.stat-mech)
[67]  arXiv:1708.01392 (replaced) [pdf, ps, other]
Title: Phonon antibunching effect in coupled nonlinear micro/nanomechanical resonator at finite temperature
Comments: 7 pages, 7 figure
Journal-ref: EPL, 119 (2017) 58001
Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[68]  arXiv:1708.01653 (replaced) [pdf, other]
Title: Strong-pinning regimes by spherical inclusions in anisotropic type-II superconductors
Comments: 24 pages, 16 figures
Subjects: Superconductivity (cond-mat.supr-con); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci); Applied Physics (physics.app-ph); Computational Physics (physics.comp-ph)
[69]  arXiv:1708.02034 (replaced) [pdf, other]
Title: Field effect induced mesoscopic devices in depleted two dimensional electron systems
Comments: 8 pages, 7 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[70]  arXiv:1708.04619 (replaced) [pdf, other]
Title: Quantum Field Theory of X-Cube Fracton Topological Order and Robust Degeneracy from Geometry
Comments: 14+6 pages, 8+3 figures; v3 fixes some minor mistakes
Journal-ref: Phys. Rev. B 96, 195139 (2017)
Subjects: Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics - Theory (hep-th)
[71]  arXiv:1708.06472 (replaced) [pdf, other]
Title: Emergence of Gapped Bulk and Metallic Side Walls in the Zeroth Landau level in Dirac and Weyl semimetals
Comments: 8 pages, 4 figures
Journal-ref: Phys. Rev. B 96, 195143 (2017)
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[72]  arXiv:1708.09039 (replaced) [pdf, other]
Title: Electron temperature and tunnel coupling dependence of zero-bias and almost-zero-bias conductance peaks in Majorana nanowires
Comments: 21 pages, 30 figures. Published version
Journal-ref: Phys. Rev. B 96, 184520 (2017)
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Superconductivity (cond-mat.supr-con)
[73]  arXiv:1709.01297 (replaced) [pdf, ps, other]
Title: Photoinduced absorptions inside the Mott gap in the two-dimensional extended Hubbard model
Comments: 7pages, 6figures
Journal-ref: Phys. Rev. B 96, 195141 (2017)
Subjects: Strongly Correlated Electrons (cond-mat.str-el)
[74]  arXiv:1709.01516 (replaced) [pdf]
Title: Antiferromagnetic order in the Hubbard Model on the Penrose Lattice
Comments: 17 pages, 21 figures
Subjects: Strongly Correlated Electrons (cond-mat.str-el)
[75]  arXiv:1709.03840 (replaced) [pdf, ps, other]
Title: Mathematical models and numerical methods for spinor Bose-Einstein condensates
Comments: A review paper with 68 pages
Subjects: Quantum Gases (cond-mat.quant-gas)
[76]  arXiv:1709.05558 (replaced) [pdf, other]
Title: Quantum phase transition of chiral Majorana fermion in the presence of disorder
Comments: 8 pages, 4 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[77]  arXiv:1710.06107 (replaced) [pdf, other]
Title: Intra-cone transition effect to magnetoconductivity in Dirac semimetal
Comments: 20 pages, 5 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics - Phenomenology (hep-ph)
[78]  arXiv:1710.08210 (replaced) [pdf, ps, other]
Title: Magnetic-Field-Induced Superconductivity in Ultrathin Pb Films with Magnetic Impurities
Comments: accepted for publication in Phys. Rev. Lett
Subjects: Superconductivity (cond-mat.supr-con)
[79]  arXiv:1710.08485 (replaced) [pdf, other]
Title: Making Faces: Universal Inverse Design of Surfaces with Thin Nematic Elastomer Sheets
Comments: 16 pages, 4 figures + supplementary materials (16 pages, 7 figures)
Subjects: Soft Condensed Matter (cond-mat.soft)
[80]  arXiv:1710.10241 (replaced) [pdf, ps, other]
Title: Doping Li-rich cathode material Li$_2$MnO$_3$: Interplay between lattice site preference, electronic structure, and delithiation mechanism
Authors: Khang Hoang
Comments: 11 pages, 10 figures; minor changes
Subjects: Materials Science (cond-mat.mtrl-sci)
[81]  arXiv:1710.10414 (replaced) [pdf, ps, other]
Title: Exact evaluation of the causal spectrum and localization properties of electronic states on a scale-free network
Comments: BJ Yang and PC Xie contribute equally to this work
Subjects: Statistical Mechanics (cond-mat.stat-mech)
[82]  arXiv:1711.02874 (replaced) [pdf, ps, other]
Title: Excited states of two-dimensional solitons supported by the spin-orbit coupling and field-induced dipole-dipole repulsion
Comments: 8 pages, 3 figures, and 73 references
Subjects: Quantum Gases (cond-mat.quant-gas); Pattern Formation and Solitons (nlin.PS); Optics (physics.optics)
[83]  arXiv:1711.04771 (replaced) [pdf, other]
Title: Next Generation Dynamical Mean-Field Theory Simulations with the Adaptive Sampling Configuration Interaction Method
Comments: 4+ pages, 4 figures, supplemental information
Subjects: Strongly Correlated Electrons (cond-mat.str-el); Materials Science (cond-mat.mtrl-sci); Quantum Physics (quant-ph)
[84]  arXiv:1711.06949 (replaced) [pdf, ps, other]
Title: Relaxation dynamics of closed diffusive systems with infinitesimal Langmuir kinetics
Comments: 7 pages, 5 figures
Subjects: Statistical Mechanics (cond-mat.stat-mech)
[85]  arXiv:1711.07126 (replaced) [pdf, ps, other]
Title: Exact results for a fractional derivative of elementary functions
Subjects: Mathematical Physics (math-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[86]  arXiv:1711.07665 (replaced) [pdf, other]
Title: Superconducting Gatemon Qubit based on a Proximitized Two-Dimensional Electron Gas
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)
[87]  arXiv:1711.07800 (replaced) [pdf, other]
Title: Equilibration of quantum hall edge states and its conductance fluctuations in graphene p-n junctions
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
[88]  arXiv:1711.07860 (replaced) [pdf, other]
Title: Jack on a Devil's staircase
Comments: Based on a talk given at the congress of the Department of Physics (2017), Universit\`a degli studi di Milano
Subjects: Strongly Correlated Electrons (cond-mat.str-el)
[89]  arXiv:1711.07969 (replaced) [pdf, other]
Title: Suppression of the fieldlike spin-orbit torque efficiency due to the magnetic proximity effect in ferromagnet/platinum bilayers
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci)
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