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Quantum Physics

New submissions

[ total of 46 entries: 1-46 ]
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New submissions for Thu, 23 Nov 17

[1]  arXiv:1711.07982 [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.

[2]  arXiv:1711.07994 [pdf, other]
Title: Continuous phase-space representations for finite-dimensional quantum states and their tomography
Comments: 6 pages, 3 figures
Subjects: Quantum Physics (quant-ph)

Continuous phase spaces have become a powerful tool for describing, analyzing, and tomographically reconstructing quantum states in quantum optics and beyond. A plethora of these phase-space techniques are known, however a thorough understanding of their relations was still lacking for finite-dimensional quantum states. We present a unified approach to continuous phase-space representations which highlights their relations and tomography. The quantum-optics case is then recovered in the large-spin limit. Our results will guide practitioners to design robust innovative tomography schemes.

[3]  arXiv:1711.08017 [pdf, other]
Title: Continuous variable entanglement of counter-propagating twin beams
Comments: 14 pages, 8 figures
Subjects: Quantum Physics (quant-ph)

This work describes the continuous-variable entanglement of the counter-propagating twin beams generated in a Mirrorless Optical Parametric Oscillator below threshold, encompassing both their quadrature and photon-number correlation. In the first case, a comparison with the single-pass co-propagating geometry outlines the huge difference of the bandwidth involved and a completely different stability of the two sources with respect to the phase-angle. In the second case, stimulated by the critical divergence of the correlation time evidenced by Corti et al., we address the issue of the temporal bandwidth of the intensity squeezing.

[4]  arXiv:1711.08066 [pdf, other]
Title: Measurement Contextuality and Planck's Constant
Subjects: Quantum Physics (quant-ph)

Contextuality is a necessary resource for universal quantum computation and non-contextual quantum mechanics can be simulated efficiently by classical computers in many cases. Orders of Planck's constant, $\hbar$, can also be used to characterize the classical-quantum divide by expanding quantities of interest in powers of $\hbar$---all orders higher than $\hbar^0$ can be interpreted as quantum corrections to the order $\hbar^0$ term. We show that contextual measurements in finite-dimensional systems have formulations within the Wigner-Weyl-Moyal (WWM) formalism that require higher than order $\hbar^0$ terms to be included in order to violate the classical bounds on their expectation values. As a result, we show that contextuality as a resource is equivalent to orders of $\hbar$ as a resource within the WWM formalism. This explains why qubits can only exhibit state-independent contextuality under Pauli observables as in the Peres-Mermin square while odd-dimensional qudits can also exhibit state-dependent contextuality. In particular, we find that qubit Pauli observables lack an order $\hbar^0$ contribution in their Weyl symbol and so exhibit contextuality regardless of the state being measured. On the other hand, odd-dimensional qudit observables generally possess non-zero order $\hbar^0$ terms, and higher, in their WWM formulation, and so exhibit contextuality depending on the state measured: odd-dimensional qudit states that exhibit measurement contextuality have an order $\hbar^1$ contribution that allows for the violation of classical bounds while states that do not exhibit measurement contextuality have insufficiently large order $\hbar^1$ contributions.

[5]  arXiv:1711.08098 [pdf, ps, other]
Title: Randomized Benchmarking Using Unitary t-Design for Fidelity Estimation of Practical Quantum Circuit
Comments: 15 pages, 3 figures
Subjects: Quantum Physics (quant-ph)

Randomized benchmarking is a useful scheme for characterizing the noise in quantum system. However, it is insensitive to practical unitary errors. We propose a method of applying unitary t-design in quantum process tomography with local random unitary operator, which is constructed by a lot of nearest neighboring two-qubit unitary operators, to estimate average fidelity. This method converts the estimation of unitary errors to the analysis of pseudo-randomness about a set of unitary operators. We then give a upper bound of a diamond norm between arbitrary and invariant Haar distribution to form an \epsilon-approximate unitary t-design. We apply \epsilon-approximate unitary t-design to a large-scale quantum circuit to analysis the errors caused by practical implementation.

[6]  arXiv:1711.08112 [pdf, other]
Title: Strong unitary and overlap uncertainty relations: theory and experiment
Comments: 5 pages of main text, 4 pages of Supplemental Material
Subjects: Quantum Physics (quant-ph)

We theoretically and experimentally investigate a strong uncertainty relation valid for any $n$ unitary operators, which implies the standard uncertainty relation as a special case, and which can be written in terms of geometric phases. It is saturated by every pure state of any $n$-dimensional quantum system, generates a tight overlap uncertainty relation for the transition probabilities of any $n+1$ pure states, and gives an upper bound for the out-of-time-order correlation function. We test these uncertainty relations experimentally for photonic polarisation qubits, including the minimum uncertainty states of the overlap uncertainty relation, via interferometric measurements of generalised geometric phases.

[7]  arXiv:1711.08196 [pdf, other]
Title: Strictly local one-dimensional topological quantum error correction with symmetry-constrained cellular automata
Comments: Submission to SciPost
Subjects: Quantum Physics (quant-ph); Cellular Automata and Lattice Gases (nlin.CG)

Active quantum error correction on topological codes is one of the most promising routes to long-term qubit storage. In view of future applications, the scalability of the used decoding algorithms in physical implementations is crucial. In this work, we focus on the one-dimensional Majorana chain and construct a strictly local decoder based on a self-dual cellular automaton. We study numerically and analytically its performance and exploit these results to contrive a scalable decoder with exponentially growing decoherence times in the presence of noise. Our results pave the way for scalable and modular designs of actively corrected one-dimensional topological quantum memories.

[8]  arXiv:1711.08249 [pdf, ps, other]
Title: Vacuum fluctuations and radiation reaction contributions to the resonance dipole-dipole interaction between two atoms near a reflecting boundary
Comments: 12 pages, 12 figures
Subjects: Quantum Physics (quant-ph)

We investigate the resonance dipole-dipole interaction energy between two identical atoms, one in the ground state and the other in the excited state, interacting with the electromagnetic field in the presence of a perfectly reflecting plane boundary. The atoms are prepared in a correlated (symmetric or anti-symmetric) Bell-type state. Following a procedure due to Dalibard, Dupont-Roc, and Cohen-Tannoudji, we separate the contributions of vacuum fluctuations and radiation reaction (source) field to the resonance interaction energy between the two atoms, and show that only the source field contributes to the interatomic interaction, while vacuum field fluctuations do not. By considering specific geometric configurations of the two-atom-system with respect to the mirror and specific choices of dipole orientations, we show that the presence of the mirror significantly affects the resonance interaction energy, and that new features appear with respect to the case of atoms in free space, for example a change in the spatial dependence of the interaction. Our findings also suggest that the presence of a boundary can be exploited to tailor and control the resonance interaction between two atoms, as well as the related energy transfer process. Possibility to observe these phenomena is also discussed.

[9]  arXiv:1711.08255 [pdf, other]
Title: High-speed and high-performance polarization-based quantum key distribution system without side channel effects caused by multiple lasers
Subjects: Quantum Physics (quant-ph)

Side channel effects such as temporal disparity and intensity fluctuation of photon pulses caused by random bit generation with multiple laser diodes in high-speed polarization-based BB84 quantum key distribution (QKD) systems can be eliminated by increasing DC bias current condition. However, background photons caused by the spontaneous emission process under high DC bias current degrade the performance of the QKD systems. In this study, we investigated, for the first time, the effects of spontaneously emitted photons on the system performance in a high-speed QKD system at a clock rate of 400 MHz. Also, we further show improvements of system performance without side channel effects by utilizing temporal filtering technique with real-time FPGA signal processing.

[10]  arXiv:1711.08276 [pdf, ps, other]
Title: Optimization of Quantum Key Distribution Protocols
Comments: 29 pages and 10 figures
Subjects: Quantum Physics (quant-ph)

Quantum Key Distribution is a practically implementable information-theoretic secure method for transmitting keys to remote partners performing quantum communication. After examining various protocols from the simplest such as QC and BB84 we move on to describe BBM92, DPSK, SARG04 and finally MDI from the largest possible communication distance and highest secret key bitrate. We discuss how any protocol can be optimized by reviewing the various steps and underlying assumptions proper to every protocol with the corresponding consequence in each case.

[11]  arXiv:1711.08281 [pdf, ps, other]
Title: Analysis of atmospheric effects on satellite based quantum communication: A comparative study
Subjects: Quantum Physics (quant-ph); Information Theory (cs.IT)

Quantum Key Distribution (QKD) is a key exchange protocol which is implemented over free space optical links and optical fiber cable. When direct communication is not possible, QKD is performed over fiber cables, but the imperfections in detectors used at receiver side and also the material properties of fiber cables limit the long distance communication. Free space based quan- tum key distribution is free from such limitations, and can pave way for satellite based quantum communication to set up a global network for sharing secret messages. To implement free space optical (FSO) links, it is essential to study the effect of atmospheric turbulence. Here, an analysis is made for satellite based quantum communication using QKD protocols. The results obtained indicate that SARG04 protocol is an effective approach for satellite based quantum communication.

[12]  arXiv:1711.08302 [pdf, other]
Title: Generation of short hard X-ray pulses of tailored duration using a Mössbauer source
Comments: 8 pages, 6 figures
Subjects: Quantum Physics (quant-ph)

We theoretically investigate a scheme for generations of single hard X-ray pulses of controllable duration in the range of 1 ns - 100 ns from a radioactive M\"ossbauer source. The scheme uses a magnetically perturbed $^{57}$FeBO$_3$ crystal illuminated with recoilless 14.4 keV photons from a radioisotope $^{57}$Co nuclide. Such compact X-ray source is useful for the extension of quantum optics to 10 keV energy scale which has been spotlighted in recent years. So far, experimental achievements are mostly performed in synchrotron radiation facilities. However, tabletop and portable hard X-ray sources are still limited for time-resolved measurements and for implementing coherent controls over nuclear quantum optics systems. The availability of compact hard X-ray sources may become the engine to apply schemes of quantum information down to the subatomic scale. We demonstrate that the present method is versatile and provides an economic solution utilizing a M\"ossbauer source to perform time-resolved nuclear scattering, to produce suitable pulses for photon storage and to flexibly generate X-ray single-photon entanglement.

[13]  arXiv:1711.08318 [pdf, ps, other]
Title: Local box-counting dimensions of discrete quantum eigenvalue spectra: Analytical connection to quantum spectral statistics
Subjects: Quantum Physics (quant-ph); Chaotic Dynamics (nlin.CD)

Two decades ago, Wang and Ong [Phys. Rev. A 55, 1522 (1997)] hypothesized that the local box-counting dimension of a discrete quantum spectrum should depend exclusively on the nearest-neighbor spacing distribution (NNSD) of the spectrum. In this paper, we validate their hypothesis by deriving an explicit formula for the local box-counting dimension of a countably-infinite discrete quantum spectrum. This formula expresses the local box-counting dimension of a spectrum in terms of single and double integrals of the NNSD of the spectrum. As applications, we derive an analytical formula for Poisson spectra and closed-form approximations to the local box-counting dimension for spectra having Gaussian orthogonal ensemble (GOE), Gaussian unitary ensemble (GUE), and Gaussian symplectic ensemble (GSE) spacing statistics. In the Poisson and GOE cases, we compare our theoretical formulas with the published numerical data of Wang and Ong and observe excellent agreement between their data and our theory. We also study numerically the local box-counting dimensions of the Riemann zeta function zeros and the alternate levels of GOE spectra, which are often used as numerical models of spectra possessing GUE and GSE spacing statistics, respectively. In each case, the corresponding theoretical formula is found to accurately describe the numerically-computed local box-counting dimension.

[14]  arXiv:1711.08320 [pdf, other]
Title: Distribution of Off-Diagonal Cross Sections in Quantum Chaotic Scattering: Exact Results and Data Comparison
Subjects: Quantum Physics (quant-ph)

The recently derived distributions for the scattering-matrix elements in quantum chaotic systems are not accessible in the majority of experiments, whereas the cross sections are. We analytically compute distributions for the off-diagonal cross sections in the Heidelberg approach, which is ap- plicable to a wide range of quantum chaotic systems. We thus eventually fully solve a problem which already arose more than half a century ago in compound-nucleus scattering. We compare our results with data from microwave and compound-nucleus experiments, particularly addressing the transition from isolated resonances towards the Ericson regime of strongly overlapping ones.

[15]  arXiv:1711.08351 [pdf, ps, other]
Title: Efficient decoding of random errors for quantum expander codes
Comments: 31 pages
Subjects: Quantum Physics (quant-ph); Information Theory (cs.IT)

We show that quantum expander codes, a constant-rate family of quantum LDPC codes, with the quasi-linear time decoding algorithm of Leverrier, Tillich and Z\'emor can correct a constant fraction of random errors with very high probability. This is the first construction of a constant-rate quantum LDPC code with an efficient decoding algorithm that can correct a linear number of random errors with a negligible failure probability. Finding codes with these properties is also motivated by Gottesman's construction of fault tolerant schemes with constant space overhead.
In order to obtain this result, we study a notion of $\alpha$-percolation: for a random subset $W$ of vertices of a given graph, we consider the size of the largest connected $\alpha$-subset of $W$, where $X$ is an $\alpha$-subset of $W$ if $|X \cap W| \geq \alpha |X|$.

[16]  arXiv:1711.08399 [pdf, ps, other]
Title: Completely subradiant multi-atom architectures through 2D photonic crystals
Authors: F. Galve, R. Zambrini
Subjects: Quantum Physics (quant-ph)

Inspired by recent advances in the manipulation of atoms trapped near 1D waveguides and pro- posals to use surface acoustic waves on piezoelectric substrates for the same purpose, we show the potential of two-dimensional platforms. We exploit the directional emission of atoms near photonic crystal slabs with square symmetry to build perfect subradiant states of 2 distant atoms, possible in 2D only for finite lattices with reflecting boundaries. We also show how to design massively parallel 1D arrays of atoms above a single crystal, useful for multi-port output of nonclassical light, by ex- ploiting destructive interference of guided resonance modes due to finite size effects. Directionality of the emission is shown to be present whenever a linear iso-frequency manifold is present in the dispersion relation of the crystal. Multi-atom radiance properties can be obtained from a simple cross-talk coefficient of a master equation, which we compare with exact atom-crystal dynamics, showing its predictive power.

[17]  arXiv:1711.08427 [pdf, ps, other]
Title: Generalized Formalism for Information Backflow in assessing Markovianity and its equivalence to Divisibility
Comments: 7 pages including appendices, 1 figure, comments and suggestions are welcome
Subjects: Quantum Physics (quant-ph)

We present a general framework for the information backflow (IB) approach of Markovianity, that not only includes a large number, if not all, of IB prescriptions proposed so far, but also is equivalent to CP-divisibility for invertible evolutions. Following the common approach of IB, where monotonic decay of some physical property is seen as the definition of Markovianity, we propose, in our framework, a general description of what should be called a proper `physicality quantifier' to define Markovianity. We elucidate different properties of our framework and use it to show that generalized trace-distance measure in $2$ dimension and quantum mutual information, for invertible dynamics, in any dimension serve as sufficient criteria for IB-Markovianity for a number of prescriptions, suggested earlier in literature.

Cross-lists for Thu, 23 Nov 17

[18]  arXiv:1711.07988 (cross-list from cond-mat.quant-gas) [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.

[19]  arXiv:1711.08027 (cross-list from cond-mat.stat-mech) [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.

[20]  arXiv:1711.08039 (cross-list from cs.CC) [pdf, other]
Title: Alternating minimization, scaling algorithms, and the null-cone problem from invariant theory
Comments: 48 pages
Subjects: Computational Complexity (cs.CC); Mathematical Physics (math-ph); Algebraic Geometry (math.AG); Quantum Physics (quant-ph)

Alternating minimization heuristics seek to solve a (difficult) global optimization task through iteratively solving a sequence of (much easier) local optimization tasks on different parts (or blocks) of the input parameters. While popular and widely applicable, very few examples of this heuristic are rigorously shown to converge to optimality, and even fewer to do so efficiently.
In this paper we present a general framework which is amenable to rigorous analysis, and expose its applicability. Its main feature is that the local optimization domains are each a group of invertible matrices, together naturally acting on tensors, and the optimization problem is minimizing the norm of an input tensor under this joint action. The solution of this optimization problem captures a basic problem in Invariant Theory, called the null-cone problem.
This algebraic framework turns out to encompass natural computational problems in combinatorial optimization, algebra, analysis, quantum information theory, and geometric complexity theory. It includes and extends to high dimensions the recent advances on (2-dimensional) operator scaling.
Our main result is a fully polynomial time approximation scheme for this general problem, which may be viewed as a multi-dimensional scaling algorithm. This directly leads to progress on some of the problems in the areas above, and a unified view of others. We explain how faster convergence of an algorithm for the same problem will allow resolving central open problems.
Our main techniques come from Invariant Theory, and include its rich non-commutative duality theory, and new bounds on the bitsizes of coefficients of invariant polynomials. They enrich the algorithmic toolbox of this very computational field of mathematics, and are directly related to some challenges in geometric complexity theory (GCT).

[21]  arXiv:1711.08120 (cross-list from physics.optics) [pdf, other]
Title: Sorting photons by radial quantum number
Subjects: Optics (physics.optics); Quantum Physics (quant-ph)

The Laguerre-Gaussian (LG) modes constitute a complete basis set for representing the transverse structure of a {paraxial} photon field in free space. Earlier workers have shown how to construct a device for sorting a photon according to its azimuthal LG mode index, which describes the orbital angular momentum (OAM) carried by the field. In this paper we propose and demonstrate a mode sorter based on the fractional Fourier transform (FRFT) to efficiently decompose the optical field according to its radial profile. We experimentally characterize the performance of our implementation by separating individual radial modes as well as superposition states. The reported scheme can, in principle, achieve unit efficiency and thus can be suitable for applications that involve quantum states of light. This approach can be readily combined with existing OAM mode sorters to provide a complete characterization of the transverse profile of the optical field.

[22]  arXiv:1711.08259 (cross-list from cond-mat.mes-hall) [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.

Replacements for Thu, 23 Nov 17

[23]  arXiv:1506.02910 (replaced) [pdf, other]
Title: Cavity-mediated collective laser-cooling of a non-interacting atomic gas inside an asymmetric trap to very low temperatures
Comments: 12 pages, 3 figures, final version
Subjects: Quantum Physics (quant-ph)
[24]  arXiv:1602.03783 (replaced) [src]
Title: No-signaling versus quantum constraints for spatio-temporal correlations caused by weak measurement
Comments: The paper is superseded by arXiv:1702.00078
Journal-ref: Phys. Rev. A 96, 012124 (2017)
Subjects: Quantum Physics (quant-ph)
[25]  arXiv:1607.02094 (replaced) [pdf, other]
Title: Magneto-optic effects of the Cosmic Microwave Background
Authors: Damian Ejlli
Comments: Additional references added. More details have been added in the introduction and discussion sections. Slightly reduced version with respect to previous one. Unchanged final results
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); Quantum Physics (quant-ph)
[26]  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)
[27]  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)
[28]  arXiv:1703.07673 (replaced) [pdf, other]
Title: Quantum dynamics of two coupled spins under controllable and fluctuating magnetic fields
Comments: 11 pages, 5 figures
Subjects: Quantum Physics (quant-ph)
[29]  arXiv:1704.08291 (replaced) [pdf, other]
Title: Dynamics and thermodynamics of a central spin immersed in a spin bath
Comments: Close to published version
Journal-ref: Phys. Rev. A 96, 052125 (2017)
Subjects: Quantum Physics (quant-ph)
[30]  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)
[31]  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)
[32]  arXiv:1705.10953 (replaced) [pdf, other]
Title: The effects of filtering on the purity of heralded single photons from parametric sources
Comments: 9 pages, 9 figures
Journal-ref: Phys. Rev. A 96, 053842 (2017)
Subjects: Quantum Physics (quant-ph)
[33]  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)
[34]  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)
[35]  arXiv:1707.07859 (replaced) [pdf, other]
Title: Wigner Function Reconstruction in Levitated Optomechanics
Comments: 9 pages, 3 figures
Journal-ref: Quantum Measurements and Quantum Metrology, 4(1), pp. 17-25 (2017)
Subjects: Quantum Physics (quant-ph); Optics (physics.optics)
[36]  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)
[37]  arXiv:1708.05103 (replaced) [pdf, other]
Title: Completeness and Nonclassicality of Coherent States for Generalized Oscillator Algebras
Comments: 26 pages, 10 figures, minor changes, misprints corrected
Subjects: Quantum Physics (quant-ph)
[38]  arXiv:1708.06507 (replaced) [pdf, other]
Title: Quantum phase space with a basis of Wannier functions
Authors: Yuan Fang, Fan Wu, Biao Wu
Comments: 6 figures
Subjects: Quantum Physics (quant-ph)
[39]  arXiv:1709.03276 (replaced) [pdf, ps, other]
Title: Quantum neural networks driven by information reservoir
Comments: 10 Pages, 4 Figures
Subjects: Quantum Physics (quant-ph)
[40]  arXiv:1709.03348 (replaced) [pdf, other]
Title: Relativity, Anomalies and Objectivity Loophole in Recent Tests of Local Realism
Authors: Adam Bednorz
Comments: 6 pages, 3 figures, submitted to the special issue of De Gruyter Open Physics, Ever-New "Loopholes" in Bell's Argument and Experimental Tests
Journal-ref: Open Physics 15, 692 (2017)
Subjects: Quantum Physics (quant-ph)
[41]  arXiv:1710.02813 (replaced) [pdf, other]
Title: Einstein-Podolsky-Rosen steering and Bell nonlocality of two macroscopic mechanical oscillators in optomechanical systems
Authors: Jie Li, Shi-Yao Zhu
Comments: More references added. To appear in PRA
Subjects: Quantum Physics (quant-ph)
[42]  arXiv:1710.09053 (replaced) [pdf, other]
Title: Controlled Quantum Search
Authors: K. de Lacy, L. Noakes
Comments: 7 pages, 2 figures
Subjects: Quantum Physics (quant-ph)
[43]  arXiv:1711.00732 (replaced) [pdf, ps, other]
Title: Experimental and theoretical comparison of the cooling performance between standard and double-bright EIT cooling
Comments: 15 pages, 13 figures. Minor changes in the text, new title, and supplementary material moved to the appendix. Results unchanged from first version
Subjects: Quantum Physics (quant-ph); Atomic Physics (physics.atom-ph)
[44]  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)
[45]  arXiv:1711.06676 (replaced) [pdf, ps, other]
Title: Sidebands suppression of 852 nm Cesium Faraday anomalous dispersion optical filter by argon gas
Subjects: Atomic Physics (physics.atom-ph); Quantum Physics (quant-ph)
[46]  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)
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