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Quantum Physics

New submissions

[ total of 39 entries: 1-39 ]
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New submissions for Mon, 19 Feb 18

[1]  arXiv:1802.05710 [pdf, ps, other]
Title: Symmetry and decoherence-free subspaces in quantum neural networks
Comments: LaTex, 11 pages, 6 eps figures
Subjects: Quantum Physics (quant-ph)

Evolution of quantum states of array of quantum dots is analyzed by means of numerical solution of the von Neumann equation. For two qubit system with dipole-dipole interaction and common phonon bath the evolution of the symmetric state $\frac{\uparrow\downarrow+\downarrow\uparrow}{\sqrt{2}}$ leads to the mixture of the triplet states, leaving the singlet decoupled. For three qubit system ($D_{1/2}^{\otimes3}=D_{3/2}+2D_{1/2}$) with common phonon bath we observed similar effects within the quartet state $D_{3/2}$ if all qubits were symmetrically connected.

[2]  arXiv:1802.05719 [pdf, other]
Title: Generic emergence of objectivity of observables in infinite dimensions
Comments: 15 pages, 3 figures
Subjects: Quantum Physics (quant-ph)

Quantum Darwinism posits that information becomes objective whenever multiple observers indirectly probe a quantum system by each measuring a fraction of the environment. It was recently shown that objectivity of observables emerges generically from the mathematical structure of quantum mechanics, whenever the system of interest has finite dimensions and the number of environment fragments is large [Brand\~ao et. al. (2015), Nat. Commun. 6, 7908]. Despite the importance of this result, it necessarily excludes many practical systems of interest that live in infinite dimensions, including harmonic oscillators. Extending the study of Quantum Darwinism to infinite dimensions is a nontrivial task: we tackle it here by introducing a modified diamond norm, suitable to quantify the distinguishability of channels in infinite dimensions. We prove two theorems that bound the emergence of objectivity, first for finite energy systems, and then for systems that can only be prepared in states with an exponential energy cut-off. We show that the latter class of states includes any bounded-energy subset of single-mode Gaussian states.

[3]  arXiv:1802.05741 [pdf, other]
Title: Implementation of an efficient linear-optical quantum router
Comments: 5 pages, 5 figures + supplement
Subjects: Quantum Physics (quant-ph)

In this paper, we report on experimental implementation of a linear-optical quantum router. Our device allows single-photon polarization-encoded qubits to be routed coherently into two spatial output modes depending on the state of two identical control qubits. The polarization qubit state of the routed photon is maintained during the routing operation. The success probability of our scheme can be increased up to 25% making it the most efficient linear-optical quantum router known to this date.

[4]  arXiv:1802.05773 [pdf, other]
Title: Experimental investigation of quantum key distribution protocols with twisted photons
Comments: 8 pages, 4 figures, 1 table
Subjects: Quantum Physics (quant-ph)

Quantum key distribution is on the verge of real world applications, where perfectly secure information can be distributed among multiple parties. Several quantum cryptographic protocols have been theoretically proposed and independently realized in different experimental conditions. Here, we develop an experimental platform based on high-dimensional orbital angular momentum states of single photons that enables implementation of multiple quantum key distribution protocols with a single experimental apparatus. Our versatile approach allows us to experimentally survey different classes of quantum key distribution techniques, such as the 1984 Bennett & Brassard (BB84), tomographic protocols including the six-state and the Singapore protocol, and a recently introduced differential phase shift (Chau15) protocol. This enables us to experimentally compare the performance of these techniques and discuss their benefits and deficiencies in terms of noise tolerance in different dimensions. Our analysis gives an overview of the available quantum key distribution protocols for photonic orbital angular momentum and highlights the benefits of the presented schemes for different implementations and channel conditions.

[5]  arXiv:1802.05779 [pdf, other]
Title: Quantum Variational Autoencoder
Comments: 12 pages, 3 figures, 2 tables
Subjects: Quantum Physics (quant-ph); Learning (cs.LG); Machine Learning (stat.ML)

Variational autoencoders (VAEs) are powerful generative models with the salient ability to perform inference. Here, we introduce a \emph{quantum variational autoencoder} (QVAE): a VAE whose latent generative process is implemented as a quantum Boltzmann machine (QBM). We show that our model can be trained end-to-end by maximizing a well-defined loss-function: a "quantum" lower-bound to a variational approximation of the log-likelihood. We use quantum Monte Carlo (QMC) simulations to train and evaluate the performance of QVAEs. To achieve the best performance, we first create a VAE platform with discrete latent space generated by a restricted Boltzmann machine (RBM). Our model achieves state-of-the-art performance on the MNIST dataset when compared against similar approaches that only involve discrete variables in the generative process. We consider QVAEs with a smaller number of latent units to be able to perform QMC simulations, which are computationally expensive. We show that QVAEs can be trained effectively in regimes where quantum effects are relevant despite training via the quantum bound. Our findings open the way to the use of quantum computers to train QVAEs to achieve competitive performance for generative models. Placing a QBM in the latent space of a VAE leverages the full potential of current and next-generation quantum computers as sampling devices.

[6]  arXiv:1802.05790 [pdf, other]
Title: OAM-enhanced estimation of sub-Heisenberg-limited angular displacement with two-mode squeezed vacuum and parity detection
Comments: 8 pages, 5 figures
Subjects: Quantum Physics (quant-ph)

We report on an OAM-enhanced scheme for angular displacement estimation based on two-mode squeezed vacuum and parity detection. The sub-Heisenberg-limited sensitivity for angular displacement estimation is obtained in an ideal situation. Several realistic factors are also considered, including photon loss, dark counts, response-time delay, and thermal photon noise. Our results indicate that the effects of the realistic factors on the sensitivity can be offset by raising OAM quantum number $\ell$. This reflects that the robustness and the practicability of the system can be improved via raising $\ell$ without changing mean photon number $N$.

[7]  arXiv:1802.05812 [pdf, ps, other]
Title: Minimal dissipation model for bipartite quantum systems at finite temperature
Comments: 9 pages, 7 figures
Subjects: Quantum Physics (quant-ph)

We consider the reduced dynamics in a bipartite quantum system (consisting of a central system and an intermediate environment) coupled to a heat bath at finite temperature. To describe this situation, in the simplest possible -- yet physically meaningful way, we introduce the "depolarizing heat bath" as a new minimal dissipation model. We conjecture that at sufficiently strong dissipation, any other dissipation model implemented in the form of a Markovian quantum master equation will become equivalent to the minimal model.
To support this conjecture, we study a two-level system coupled to an oscillator mode. For the coupling between the two parts, we consider the Jaynes-Cummings or a dephasing coupling, while the coupling to the heat bath is modeled by the quantum optical or the Caldeira-Leggett master equation (neglecting any direct coupling between central system and heat bath). We then provide ample numerical evidence, for both, model-independence and accuracy of the depolarizing heat bath model. Alongside with our study, we investigate the different coupling regimes, under which the strong coupling condition may lead to coherence and/or population stabilization.

[8]  arXiv:1802.05826 [pdf, other]
Title: Dealing with indistinguishable particles and their entanglement
Comments: 9 pages, 2 figures. Manuscript prepared following the Royal Society Meeting "Foundations of quantum mechanics and their impact on contemporary society"
Subjects: Quantum Physics (quant-ph)

Here we discuss a particle-based approach to deal with systems of many identical quantum objects (particles) which never employs labels to mark them. We show that it avoids both methodological problems and drawbacks in the study of quantum correlations associated to the standard quantum mechanical treatment of identical particles. The core of this approach is represented by the multiparticle probability amplitude whose structure in terms of single-particle amplitudes we here derive by first principles. To characterise entanglement among the identical particles, this new method utilises the same notions, such as partial trace, adopted for nonidentical ones. We highlight the connection between our approach and second quantization. We also define spin-exchanged multipartite states (SPES) which contain a generalisation of W states to identical particles. We prove that their spatial overlap plays a role on the distributed entanglement within multipartite systems and is responsible for the appearance of nonlocal quantum correlations.

[9]  arXiv:1802.05877 [pdf, ps, other]
Title: Exact analytical solution of Entanglement of Formation and Quantum Discord for Werner state and Generalized Werner-Like states
Comments: This work contain six figures and present the results of thesis doctoral
Subjects: Quantum Physics (quant-ph)

We obtained analytical expressions for Entangled of Formation (EoF) and Quantum Discord (QD) of Werner states and Generalized Werner-Like states. The optimization problem involved under the exact analytical form is obtained for both quantities. In order to illustrate the importance of our results we studied the EoF and the QD of these states. Using discrete formulation of continue states with the $f-$deformed coherent states obtained as deformed annihilation operator coherent states and as deformed displacement operator coherent states. The EoF and QD of bipartite Werner-Like states $f-$deformed coherent states are studied for the P\"{o}schl-Teller, Morse and quantum dot deformed potentials. The result obtained are compared with the case of bipartite Werner-Like coherent states.

[10]  arXiv:1802.05915 [pdf, ps, other]
Title: Superradiance-driven Phonon Laser
Comments: accepted by Chin. Phys. Lett
Subjects: Quantum Physics (quant-ph)

We propose to enhance the generation of a phonon laser by exploiting optical superradiance. In our scheme, the optomechanical cavity contains a movable membrane, which supports a mechanical mode, and the superradiance cavity can generate the coherent collective light emissions by applying a transverse pump to an ultracold intracavity atomic gas. The superradiant emission turns out to be capable of enhancing the phonon laser performance. This indicates a new way to operate a phonon laser with the assistance of coherent atomic gases trapped in a cavity or lattice potentials.

[11]  arXiv:1802.05919 [pdf, other]
Title: Quantum coherence fluctuation relations
Comments: 21 pages, 1 figure; comments are welcome
Subjects: Quantum Physics (quant-ph); Statistical Mechanics (cond-mat.stat-mech); Mathematical Physics (math-ph)

We investigate manipulations of pure quantum states under incoherent or strictly incoherent operations assisted by a coherence battery, that is, a storage device whose degree of coherence is allowed to fluctuate in the process. This leads to the derivation of fluctuation relations for quantum coherence, analogous to Jarzynski's and Crooks' relations for work in thermodynamics. Coherence is thus revealed as another instance of a physical resource, in addition to athermality and entanglement, for which a connection is established between the majorisation framework (regulating pure state transformations under suitable free operations) and the emergence of fluctuation theorems. Our study is hoped to provide further insight into the general structure of battery assisted quantum resource theories, and more specifically into the interplay between quantum coherence and quantum thermodynamics.

[12]  arXiv:1802.05928 [pdf, other]
Title: Levitated electromechanics: all-electrical cooling of levitated nano- and micro-particles
Comments: Manuscript: 13 pages, 5 figures. Supplementary material: 6 pages 3 figures
Subjects: Quantum Physics (quant-ph); Atomic Physics (physics.atom-ph)

Nano- and micro-scale particles levitated in vacuum are of great interest due to their minimal coupling to the environment, enabling ultra-sensitive force sensing and explorations of quantum physics. Typically, such particles are optically levitated and cooled through their interaction with an optical cavity or via active feedback. These methods are limited by optical absorption leading to significant heating, instabilities when operating in high vacuum, and the recoil noise of the trapping light. A limited range of materials can be optically trapped in vacuum, with materials such as metals or nanobiological objects not possible due to heavy absorption. Here we analyse a scheme which avoids these issues, by electrically cooling charged particles levitated in a quadrupole ion trap. Through simulations, we investigate both passive resistive cooling and active feedback cooling, and explore cooling limits in the presence of realistic noise. Working in cryogenic environments would allow cooling to the quantum level. This all-electrical cooling and detection platform will complement existing optomechanical schemes, act as pre-cooling for quantum applications, and enable state-of-the-art force-sensing with an electrically-networked system.

[13]  arXiv:1802.05931 [pdf, ps, other]
Title: A driven-dissipative quantum Monte Carlo method for open quantum systems
Subjects: Quantum Physics (quant-ph)

We develop a real-time Full Configuration Interaction Quantum Monte Carlo approach for the modeling of driven-dissipative open quantum systems. The method enables stochastic sampling of the Liouville-von-Neumann time evolution of the density matrix, thanks to a massively parallel algorithm, thus providing estimates of observables on the non-equilibrium steady state. We present the underlying theory, and introduce initiator technique and importance sampling to reduce the statistical error. Finally, we demonstrate the efficiency of our approach by applying it to the driven- dissipative two-dimensional XYZ spin model on lattice.

[14]  arXiv:1802.05996 [pdf, other]
Title: Dephasing mechanisms of diamond-based nuclear-spin memories for quantum networks
Comments: 11 pages, 6 figures
Subjects: Quantum Physics (quant-ph)

We probe dephasing mechanisms within a quantum network node consisting of a single nitrogen-vacancy centre electron spin that is hyperfine coupled to surrounding $^{13} \text{C}$ nuclear-spin quantum memories. Previous studies have analysed memory dephasing caused by the stochastic electron-spin reset process, which is a component of optical internode entangling protocols. Here, we find, by using dynamical decoupling techniques and exploiting phase matching conditions in the electron-nuclear dynamics, that control infidelities and quasi-static noise are the major contributors to memory dephasing induced by the entangling sequence. These insights enable us to demonstrate a 19-fold improved memory performance which is still not limited by the electron reinitialization process. We further perform pump-probe studies to investigate the spin-flip channels during the optical electron spin reset. We find that spin-flips occur via decay from the meta-stable singlet states with a branching ratio of 8(1):1:1, in contrast with previous work. These results allow us to formulate straightforward improvements to diamond-based quantum networks and similar architectures.

[15]  arXiv:1802.06002 [pdf, other]
Title: Classification with Quantum Neural Networks on Near Term Processors
Comments: 21 pages, 1 figure
Subjects: Quantum Physics (quant-ph)

We introduce a quantum neural network, QNN, that can represent labeled data, classical or quantum, and be trained by supervised learning. The quantum circuit consists of a sequence of parameter dependent unitary transformations which acts on an input quantum state. For binary classification a single Pauli operator is measured on a designated readout qubit. The measured output is the quantum neural network's predictor of the binary label of the input state. First we look at classifying classical data sets which consist of n-bit strings with binary labels. The input quantum state is an n-bit computational basis state corresponding to a sample string. We show how to design a circuit made from two qubit unitaries that can correctly represent the label of any Boolean function of n bits. For certain label functions the circuit is exponentially long. We introduce parameter dependent unitaries that can be adapted by supervised learning of labeled data. We study an example of real world data consisting of downsampled images of handwritten digits each of which has been labeled as one of two distinct digits. We show through classical simulation that parameters can be found that allow the QNN to learn to correctly distinguish the two data sets. We then discuss presenting the data as quantum superpositions of computational basis states corresponding to different label values. Here we show through simulation that learning is possible. We consider using our QNN to learn the label of a general quantum state. By example we show that this can be done. Our work is exploratory and relies on the classical simulation of small quantum systems. The QNN proposed here was designed with near-term quantum processors in mind. Therefore it will be possible to run this QNN on a near term gate model quantum computer where its power can be explored beyond what can be explored with simulation.

[16]  arXiv:1802.06011 [pdf, ps, other]
Title: A necessary condition for quantum adiabaticity applied to the Grover adiabatic search
Authors: Oleg Lychkovskiy
Subjects: Quantum Physics (quant-ph)

Numerous sufficient conditions for adiabaticity of the evolution of a driven quantum system have been known for quite a long time. In contrast, necessary adiabatic conditions are scarce. A practicable necessary condition well-suited for many-body systems has been proven recently in [Phys. Rev. Lett. 119, 200401 (2017)]. Here we tailor this condition for estimating run times of quantum adiabatic algorithms. As an illustration, the condition is applied to the adiabatic algorithm for searching in an unstructured database (adiabatic Grover search algorithm). We find that thus obtained lower bound on the run time of this algorithm reproduces $\sqrt N$ scaling ($N$ being the number of database entries) of the explicitly known optimal run time. This observation highlights the merits of the new adiabatic condition and its potential relevance to adiabatic quantum computing.

Cross-lists for Mon, 19 Feb 18

[17]  arXiv:1802.05723 (cross-list from physics.chem-ph) [pdf, ps, other]
Title: Relativistic properties of a molecule: energy, linear momentum, angular momentum and boost momentum to order $1/c^2$
Subjects: Chemical Physics (physics.chem-ph); Quantum Physics (quant-ph)

We give an explicit and general description of the energy, linear momentum, angular momentum and boost momentum of a molecule to order $1/c^2$, where it necessary to take account of kinetic contributions made by the electrons and nuclei as well as electromagnetic contributions made by the intramolecular field. A wealth of interesting subtleties are encountered that are not seen at order $1/c^0$, including relativistic Hall shifts, anomalous velocities and hidden momenta. Some of these have well known analogues in solid state physics.

[18]  arXiv:1802.05756 (cross-list from cs.LG) [pdf, other]
Title: Inferring relevant features: from QFT to PCA
Authors: Cédric Bény
Subjects: Learning (cs.LG); Quantum Physics (quant-ph); Machine Learning (stat.ML)

In many-body physics, renormalization techniques are used to extract aspects of a statistical or quantum state that are relevant at large scale, or for low energy experiments. Recent works have proposed that these features can be formally identified as those perturbations of the states whose distinguishability most resist coarse-graining. Here, we examine whether this same strategy can be used to identify important features of an unlabeled dataset. This approach indeed results in a technique very similar to kernel PCA (principal component analysis), but with a kernel function that is automatically adapted to the data, or "learned". We test this approach on handwritten digits, and find that the most relevant features are significantly better for classification than those obtained from a simple gaussian kernel.

[19]  arXiv:1802.05787 (cross-list from cond-mat.mes-hall) [pdf]
Title: Tunneling magnetoresistance enhancement of magnetic tunnel junction through heavy metal layer symmetry
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Applied Physics (physics.app-ph); Quantum Physics (quant-ph)

Spin-orbit torque magnetic random access memory (SOT-MRAM) has become the research focus due to the advantages of energy-efficient switch and prolonged endurance. The writing operation is performed by the SOT induced by the heavy metal (HM) layer, while the reading operation is based on the tunneling magnetoresistance (TMR) effect. To explore the effect of HM layer on the TMR, we built top HM/CoFe/MgO/CoFe/bottom HM hetero-junctions and investigated the TMR character by first-principles calculations. It is found that the TMR would be enhanced by the HM layer symmetry, as the TMRs in W/CoFe/MgO/CoFe/W and Ta/CoFe/MgO/CoFe/Ta are higher than that in Ta/CoFe/MgO/CoFe/W. This phenomenon is attributed to the density of scattering states (DOSS) behavior and the resonant tunneling effect in parallel condition. We also studied the influence on TMR caused by thickness variation of bottom HM layer. In Ta/W/CoFe/MgO/CoFe/W/Ta SOT-MTJs, TMR ratios oscillate with variable bottom tungsten layer thickness, while all TMRs remain high. This result indicates that the HM layer symmetry dominates TMR, not the thickness. Our investigation presents a method to enhance TMR in spin-orbit torque magnetic tunnel junction (SOT-MTJ), which would benefit the high-reliability and low-energy-consumption SOT-MRAM.

[20]  arXiv:1802.05849 (cross-list from cond-mat.mes-hall) [pdf, other]
Title: Phonon-induced decoherence of a charge quadrupole qubit
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)

Many quantum dot qubits operate in regimes where the energy splittings between qubit states are large and phonons can be the dominant source of decoherence. The recently proposed charge quadrupole qubit, based on one electron in a triple quantum dot, employs a highly symmetric charge distribution to suppress the influence of charge noise. To study the effects of phonons on the charge quadrupole qubit, we consider Larmor and Ramsey pulse sequences to identify favorable operating parameters. We show that it is possible to implement typical gates with $>99.99\%$ fidelity in the presence of phonons and charge noise.

[21]  arXiv:1802.05869 (cross-list from cond-mat.mtrl-sci) [pdf, other]
Title: Carrier driven antiferromagnetism and exchange-bias in SrRuO3/CaRuO3 heterostructures
Comments: 6 pages and 4 figures
Subjects: Materials Science (cond-mat.mtrl-sci); Strongly Correlated Electrons (cond-mat.str-el); Quantum Physics (quant-ph)

Oxide heterostructures exhibit a rich variety of magnetic and transport properties which arise due to contact at an interface. This can lead to surprising effects that are very different from the bulk properties of the materials involved. We report the magnetic properties of bilayers of SrRuO3, a well known ferromagnet, and CaRuO3, which is nominally a paramagnet. We find intriguing features that are consistent with CaRuO3 developing dual magnetic character, with both a net moment as well as antiferromagnetic order. We argue the ordered SrRuO3 layer induces an undulating polarization profile in the conduction electrons of CaRuO3, by a mechanism akin to Friedel oscillations. At low temperatures, this oscillating polarization is inherited by rigid local moments within CaRuO3, leading to a robust exchange bias. We present ab initio simulations in support of this picture. Our results demonstrate a new ordering mechanism and throw light on the magnetic character of CaRuO3 .

[22]  arXiv:1802.05954 (cross-list from cond-mat.mes-hall) [pdf, ps, other]
Title: Dynamics of decoherence of an entangled pair of qubits locally connected to a one-dimensional disordered spin chain
Comments: 10 pages and 11 figures
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Statistical Mechanics (cond-mat.stat-mech); Quantum Physics (quant-ph)

We investigate the non-equilibrium evolution of concurrence of a Bell pair constituted of two qubits, locally coupled to a one-dimensional disordered Ising spin chain, by measuring the Loschmidt echo (LE) under the scope of generalized central spin model. Our study indicates that disorder prohibits a rapid decay of entanglement in long time regime; the non-trivial outcomes associated with the Griffiths phase, appearing due to the disorder, are also analyzed by examining the temporal decay of LE. The extent of the Griffiths phase is identified by a peak in the derivative of LE. In particular, it has been observed for sudden quenching between paramagnetic and ferromagnetic phase that LE shows an exponential fall, dependent on coupling strength, in small time limit followed by a power law decay, governed by disorder strength, in the long time limit. Noticeably, for quenching inside the Griffiths phase, the LE vanishes in the late time limit and hence power law fall is absent. Additionally, we show that the Gaussian fall of LE in the ultra small time window remains unaltered even with disorder. Finally, we show LE for disordered spin chain does not sense the singular time scales that appear for clean spin chain with qubits coupled at symmetric positions.

[23]  arXiv:1802.06029 (cross-list from cond-mat.mtrl-sci) [pdf, other]
Title: Molding Molecular and Material Properties by Strong Light-Matter Coupling
Subjects: Materials Science (cond-mat.mtrl-sci); Optics (physics.optics); Quantum Physics (quant-ph)

When atoms come together and bond, we call these new states molecules, and their properties determine many aspects of our daily life. Strangely enough, it is conceivable for light and molecules to bond, creating new hybrid light-matter states with far-reaching consequences for these strongly coupled materials. Even stranger, there is no `real' light needed to obtain the effects, it simply appears from the vacuum, creating `something from nothing'. Surprisingly, the setup required to create these materials has become moderately straightforward. In its simplest form, one only needs to put a strongly absorbing material at the appropriate place between two mirrors, and quantum magic can appear. Only recently has it been discovered that strong coupling can affect a host of significant effects at a material and molecular level, which were thought to be independent of the `light' environment: phase transitions, conductivity, chemical reactions, etc. This review addresses the fundamentals of this opportunity: the quantum mechanical foundations, the relevant plasmonic and photonic structures, and a description of the various applications, connecting materials chemistry with quantum information, nonlinear optics and chemical reactivity. Ultimately, revealing the interplay between light and matter in this new regime opens attractive avenues for many applications in the material, chemical, quantum mechanical and biological realms.

[24]  arXiv:1802.06034 (cross-list from hep-th) [pdf, other]
Title: Fast Summation of Divergent Series and Resurgent Transseries in Quantum Field Theories from Meijer-G Approximants
Comments: 18 pages, 9 figures, PDFTeX
Subjects: High Energy Physics - Theory (hep-th); Mathematical Physics (math-ph); Quantum Physics (quant-ph)

We demonstrate that a Meijer-G-function-based resummation approach can be successfully applied to approximate the Borel sum of divergent series, and thus to approximate the Borel-\'Ecalle summation of resurgent transseries in quantum field theory (QFT). The proposed method is shown to vastly outperform the conventional Borel-Pad\'e and Borel-Pad\'e-\'Ecalle summation methods. The resulting Meijer-G approximants are easily parameterized by means of a hypergeometric ansatz and can be thought of as a generalization to arbitrary order of the Borel-Hypergeometric method [Mera {\it et al.} Phys. Rev. Lett. {\bf 115}, 143001 (2015)]. Here we illustrate the ability of this technique in various examples from QFT, traditionally employed as benchmark models for resummation, such as: 0-dimensional $\phi^4$ theory, $\phi^4$ with degenerate minima, self-interacting QFT in 0-dimensions, and the computation of one- and two-instanton contributions in the quantum-mechanical double-well problem.

Replacements for Mon, 19 Feb 18

[25]  arXiv:1601.07623 (replaced) [pdf, ps, other]
Title: Mechanism for Time Reparametrization Symmetry Breaking in Spinor Canonical Gravity Coupled to Long-Range Spinor Particles
Authors: Eiji Konishi
Comments: 6 pages, no figure, revtex, v5:shortened and revised
Subjects: Quantum Physics (quant-ph)
[26]  arXiv:1606.02804 (replaced) [pdf, other]
Title: Particle scattering by harmonically trapped Bose and Fermi gases
Comments: 8 pages, 4 figures; Accepted in Journal of Physics B: Atomic, Molecular and Optical Physics (2018)
Subjects: Quantum Physics (quant-ph); Quantum Gases (cond-mat.quant-gas)
[27]  arXiv:1608.08821 (replaced) [pdf]
Title: Effects of entanglement in an ideal optical amplifier
Comments: 8 pages, 3 figures
Journal-ref: Physics Letters A 382, 887 (2018)
Subjects: Quantum Physics (quant-ph)
[28]  arXiv:1703.02500 (replaced) [pdf, ps, other]
Title: Casimir interaction of strained graphene
Comments: 5 pages, 3 figures, EPL style, misprint corrected
Journal-ref: Phys.Lett. A381 (2017) 2439-2443
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); High Energy Physics - Theory (hep-th); Quantum Physics (quant-ph)
[29]  arXiv:1704.04949 (replaced) [pdf, other]
Title: Fingering instabilities and pattern formation in a two-component dipolar Bose-Einstein condensate
Comments: 9 pages, 10 figures and 4 movies
Journal-ref: Phys. Rev. A 97, 023625 (2018) (Featured in Physics & Editors' suggestion)
Subjects: Quantum Gases (cond-mat.quant-gas); Fluid Dynamics (physics.flu-dyn); Quantum Physics (quant-ph)
[30]  arXiv:1707.09247 (replaced) [pdf, other]
Title: Classical and quantum dynamics of a kicked relativistic particle in a box
Comments: arXiv admin note: text overlap with arXiv:1311.0799
Journal-ref: Phys.Lett. A, 382, 633 (2018)
Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Chaotic Dynamics (nlin.CD)
[31]  arXiv:1708.05339 (replaced) [pdf, other]
Title: Complexity Bounds on Quantum Search Algorithms in finite-dimensional Networks
Comments: 12 pages, revtex-4.1, enclosed is also a Mathematica Notebook to reproduce and experiment with the calculations; related information can be found at this http URL
Subjects: Statistical Mechanics (cond-mat.stat-mech); Computational Complexity (cs.CC); Quantum Physics (quant-ph)
[32]  arXiv:1708.05535 (replaced) [pdf, other]
Title: Accuracy of dynamical decoupling based spectroscopy of Gaussian noise
Comments: 20 pages, 9 figures, 2 appendices
Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)
[33]  arXiv:1710.04827 (replaced) [pdf, other]
Title: Analysis of Measurement-based Quantum Network Coding over Repeater Networks under Noisy Conditions
Comments: 12 pages, 17 figures
Subjects: Quantum Physics (quant-ph)
[34]  arXiv:1711.00295 (replaced) [pdf, ps, other]
Title: Analysis of quantum error correction with symmetric hypergraph states
Comments: 18 pages, 2 figures; corrected number of figures; 16.02.2018: removed minor inconsistencies in font choice, added supplemental files
Subjects: Quantum Physics (quant-ph)
[35]  arXiv:1711.01284 (replaced) [pdf, other]
Title: Quantum Quenches and Relaxation Dynamics in the Thermodynamic Limit
Comments: 5 pages, 3 figures, as published
Journal-ref: Phys. Rev. Lett. 120, 070603 (2018)
Subjects: Statistical Mechanics (cond-mat.stat-mech); Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); Quantum Physics (quant-ph)
[36]  arXiv:1712.09142 (replaced) [pdf, other]
Title: Higher-Order Interactions in Quantum Optomechanics: Application of Operator Method
Subjects: Quantum Physics (quant-ph)
[37]  arXiv:1802.01326 (replaced) [pdf, other]
Title: Beyond-PFA Casimir Force between two spheres at finite temperature
Authors: Giuseppe Bimonte
Comments: 11 pages, 3 figures, an error in Eq. (8) has been corrected
Subjects: Quantum Physics (quant-ph)
[38]  arXiv:1802.03354 (replaced) [pdf, ps, other]
Title: Electron Spin Coherences in Rare-Earth Optically Excited States for Microwave to Optical Quantum Transducers
Subjects: Quantum Physics (quant-ph)
[39]  arXiv:1802.05293 (replaced) [pdf, other]
Title: Symmetry-protected coherent relaxation of open quantum systems
Comments: 8 pages, 3 figures
Subjects: Quantum Physics (quant-ph); Statistical Mechanics (cond-mat.stat-mech)
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