Showing 2021 · quant-phShow all

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quant-ph2021★ 15 cited

Chaos in a deformed Dicke model

Ángel L. Corps, Rafael A. Molina, Armando Relaño

The critical behavior in an important class of excited state quantum phase transitions is signaled by the presence of a new constant of motion only at one side of the critical ener…

quant-ph2021★ 28 cited

Optimal Thresholds for Fracton Codes and Random Spin Models with Subsystem Symmetry

Hao Song, Janik Schönmeier-Kromer, Ke Liu +3

Fracton models provide examples of novel gapped quantum phases of matter that host intrinsically immobile excitations and therefore lie beyond the conventional notion of topologica…

quant-ph2021★ 3 cited

Robust quantum metrology with random Majorana constellations

A. Z. Goldberg, J. R. Hervas, Ángel S Sanz +8

Even the most classical states are still governed by quantum theory. A number of physical systems can be described by their Majorana constellations of points on the surface of a sp…

quant-ph2021★ 25 cited

Entropy decay for Davies semigroups of a one dimensional quantum lattice

Ivan Bardet, Ángela Capel, Li Gao +3

Given a finite-range, translation-invariant commuting system Hamiltonians on a spin chain, we show that the Davies semigroup describing the reduced dynamics resulting from the join…

quant-ph2021★ 3 cited

Quantum-classical entropy analysis for nonlinearly-coupled continuous-variable bipartite systems

A. S. Sanz

The correspondence principle plays a fundamental role in quantum mechanics, which naturally leads us to inquire whether it is possible to find or determine close classical analogs…

quant-ph2021★ 13 cited

Quantumness Beyond Entanglement: The Case of Symmetric States

Aaron Z. Goldberg, Markus Grassl, Gerd Leuchs +1

It is nowadays accepted that truly quantum correlations can exist even in the absence of entanglement. For the case of symmetric states, a physically trivial unitary transformation…

quant-ph2021★ 7 cited

Maximal gap between local and global distinguishability of bipartite quantum states

Willian H. G. Corrêa, Ludovico Lami, Carlos Palazuelos

We prove a tight and close-to-optimal lower bound on the effectiveness of local quantum measurements (without classical communication) at discriminating any two bipartite quantum s…

quant-ph2021★ 9 cited

TFermion: A non-Clifford gate cost assessment library of quantum phase estimation algorithms for quantum chemistry

Pablo A. M. Casares, Roberto Campos, M. A. Martin-Delgado

Quantum Phase Estimation is one of the most useful quantum computing algorithms for quantum chemistry and as such, significant effort has been devoted to designing efficient implem…

quant-ph2021★ 9 cited

Spectral single photons characterization using generalized Hong, Ou and Mandel interferometry

Nicolas Fabre

New methods are proposed to characterize the spectral-temporal distribution of single photons. The presented protocols take advantage of spectral filtering, frequency entanglement…

quant-ph2021★ 43 cited

Entanglement and superposition are equivalent concepts in any physical theory

Guillaume Aubrun, Ludovico Lami, Carlos Palazuelos +1

We prove that any two general probabilistic theories (GPTs) are entangleable, in the sense that their composite exhibits either entangled states or entangled measurements, if and o…

quant-ph2021

Coherence, nonclassicality and metrological resolution

Laura Ares, Alfredo Luis

We demonstrate the simple and deep equivalence between quantum coherence and nonclassicality and the definite way in which they determine metrological resolution. Moreover, we defi…

quant-ph2021★ 18 cited

Quantum collisional thermostats

Jorge Tabanera, Ines Luque, Samuel L. Jacob +3

Collisional reservoirs are becoming a major tool for modelling open quantum systems. In their simplest implementation, an external agent switches on, for a given time, the interact…

quant-ph2021★ 6 cited

From polarization multipoles to higher-order coherences

Aaron Z. Goldberg, Andrei B. Klimov, Hubert de Guise +3

We demonstrate that the multipoles associated with the density matrix are truly observable quantities that can be unambiguously determined from intensity moments. Given their corre…

quant-ph2021★ 19 cited

Taming singularities of the quantum Fisher information

Aaron Z. Goldberg, José L. Romero, Ángel S. Sanz +1

Quantum Fisher information matrices (QFIMs) are fundamental to estimation theory: they encode the ultimate limit for the sensitivity with which a set of parameters can be estimated…

quant-ph2021★ 11 cited

Quantum scattering as a work source

Samuel L. Jacob, Massimiliano Esposito, Juan M. R. Parrondo +1

We consider a collision between a moving particle and a fixed system, each having internal degrees of freedom. We identify the regime where the motion of the particle acts as a wor…

quant-ph2021★ 8 cited

The time traveler's guide to the quantization of zero modes

Ana Alonso-Serrano, Erickson Tjoa, Luis J. Garay +1

We study the relationship between the quantization of a massless scalar field on the two-dimensional Einstein cylinder and in a spacetime with a time machine. We find that the latt…

quant-ph2021★ 72 cited

A detector-based measurement theory for quantum field theory

José Polo-Gómez, Luis J. Garay, Eduardo Martín-Martínez

We propose a measurement theory for quantum fields based on measurements made with localized non-relativistic systems that couple covariantly to quantum fields (like the Unruh-DeWi…

quant-ph2021★ 39 cited

Single-photon nonlocality in quantum networks

Paolo Abiuso, Tamás Kriváchy, Emanuel-Cristian Boghiu +3

The state obtained when a single photon impinges on a balanced beamsplitter is often known as single-photon entangled and its nonlocal properties have been the subject of intense d…

quant-ph2021★ 38 cited

Photon-mediated Stroboscopic Quantum Simulation of a Lattice Gauge Theory

Tsafrir Armon, Shachar Ashkenazi, Gerardo García-Moreno +2

Quantum simulation of lattice gauge theories (LGTs), aiming at tackling non-perturbative particle and condensed matter physics, has recently received a lot of interest and attentio…

quant-ph2021★ 1 cited

Quantum conditional probabilities

Ignacio Pérez, Alfredo Luis

We investigate the consistency of conditional quantum probabilities. This is whether there is compatibility between the Kolmogorov-Bayes conditional probabilities and the Born rule…

quant-ph2021★ 12 cited

Inferring work by quantum superposing forward and time-reversal evolutions

Giulia Rubino, Gonzalo Manzano, Lee A. Rozema +3

The study of thermodynamic fluctuations allows one to relate the free energy difference between two equilibrium states with the work done on a system through processes far from equ…

quant-ph2021★ 9 cited

Thermalization in Kitaev's quantum double models via Tensor Network techniques

Angelo Lucia, David Pérez-García, Antonio Pérez-Hernández

We show that the Davies generator associated to any 2D Kitaev's quantum double model has a non-vanishing spectral gap in the thermodynamic limit. This validates rigorously the exte…

quant-ph2021★ 5 cited

Continuous time crystal from a spontaneous many-body Floquet state

J. R. M. de Nova, F. Sols

Floquet driven systems represent an extremely interesting arena to study out-of-equilibrium phenomena. For instance, they provide realizations of discrete time crystals, where the…

quant-ph2021★ 3 cited

When quantum state tomography benefits from willful ignorance

L. Motka, M. Paur, J. Rehacek +2

We show that quantum state tomography with perfect knowledge of the measurement apparatus proves to be, in some instances, inferior to strategies discarding all information about t…