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Dynamical quantum phase transitions occur in dynamically evolving quantum systems when non-analyticities occur at critical times in the return rate, a dynamical analogue of the free energy. This extension of the concept of phase transitions…

Mesoscale and Nanoscale Physics · Physics 2023-11-10 T. Masłowski , N. Sedlmayr

The theory of quantum quenches in near-critical one-dimensional systems formulated in [J. Phys. A 47 (2014) 402001] yields analytic predictions for the dynamics, unveils a qualitative difference between non-interacting and interacting…

Statistical Mechanics · Physics 2017-02-07 Gesualdo Delfino , Jacopo Viti

Quantum phase transitions are central to our understanding of why matter at very low temperatures can exhibit starkly different properties upon small changes of microscopic parameters. Accurately locating those transitions is challenging…

Statistical Mechanics · Physics 2021-09-23 Asmi Haldar , Krishnanand Mallayya , Markus Heyl , Frank Pollmann , Marcos Rigol , Arnab Das

We study the quantum critical behaviour of the Dicke Hamiltonian, with finite number of atoms and explore the signature of quantum chaos using measures like the ground state fidelity and the Loschmidt echo. We show that both these…

Statistical Mechanics · Physics 2014-12-22 Utso Bhattacharya , Sayak Dasgupta , Amit Dutta

We employ the Loschmidt Echo, i.e. the signal recovered after the reversal of an evolution, to identify and quantify the processes contributing to decoherence. This procedure, which has been extensively used in single particle physics, is…

Quantum Physics · Physics 2012-07-25 Pablo R. Zangara , Axel D. Dente , Patricia R. Levstein , Horacio M. Pastawski

The Loschmidt echo (LE) is a measure of the sensitivity of quantum mechanics to perturbations in the evolution operator. It is defined as the overlap of two wave functions evolved from the same initial state but with slightly different…

Quantum Physics · Physics 2007-05-23 Fernando M. Cucchietti

The standard phase-ordering process is obtained by quenching a system, like the Ising model, to below the critical point. This is usually done with periodic boundary conditions to insure ergodicity breaking in the low temperature phase.…

Statistical Mechanics · Physics 2020-07-29 Annalisa Fierro , Antonio Coniglio , Marco Zannetti

We investigate large deviations of the work performed in a quantum quench across two different phases separated by a quantum critical point, using as example the Dicke model quenched from its superradiant to its normal phase. We extract the…

Statistical Mechanics · Physics 2020-02-10 P. Rotondo , J. Minar , J. P. Garrahan , I. Lesanovsky , M. Marcuzzi

In this review, we study some aspects of the non-equilibrium dynamics of quantum systems. In particular, we consider the effect of varying a parameter in the Hamiltonian of a quantum system which takes it across a quantum critical point or…

Statistical Mechanics · Physics 2015-05-14 Shreyoshi Mondal , Diptiman Sen , K. Sengupta

We study the dynamical response of a system to a sudden change of the tuning parameter $\lambda$ starting (or ending) at the quantum critical point. In particular we analyze the scaling of the excitation probability, number of excited…

Statistical Mechanics · Physics 2010-01-20 C. De Grandi , V. Gritsev , A. Polkovnikov

We present a characterization of quantum phase transitions in terms of the the overlap function between two ground states obtained for two different values of external parameters. On the examples of the Dicke and XY models, we show that the…

Quantum Physics · Physics 2009-11-11 Paolo Zanardi , Nikola Paunković

A universal relation is established between the quantum work probability distribution of an isolated driven quantum system and the Loschmidt echo dynamics of a two-mode squeezed state. When the initial density matrix is canonical, the…

Quantum Physics · Physics 2018-08-24 Aurélia Chenu , Iñigo L. Egusquiza , Javier Molina-Vilaplana , Adolfo del Campo

In time-independent quantum systems, entanglement entropy possesses an inherent scaling symmetry that the energy of the system does not have. The symmetry also assures that entropy divergence can be associated with the zero modes. We…

High Energy Physics - Theory · Physics 2023-07-28 S. Mahesh Chandran , S. Shankaranarayanan

We investigate finite size effects in quantum quenches on the basis of simple energetic arguments. Distinguishing between the low-energy part of the excitation spectrum, below a microscopic energy-scale, and the high-energy regime enables…

Quantum Gases · Physics 2010-05-21 Guillaume Roux

In this work we present a thorough analysis of the phase transitions that occur in a ferromagnetic 2D Ising model, with only nearest-neighbors interactions, in the framework of the Tsallis nonextensive statistics. We performed Monte Carlo…

Statistical Mechanics · Physics 2011-07-01 N. Crokidakis , D. O. Soares-Pinto , M. S. Reis , A. M. Souza , R. S. Sarthour , I. S. Oliveira

We investigate the nonequilibrium dynamics induced by a finite-time linear quench in the XY chain. Initially, we examine the dynamical quantum phase transition, characterized by the nonanalytic behavior of the Loschmidt amplitude. We find…

Statistical Mechanics · Physics 2024-11-19 Kaiyuan Cao , Peiqing Tong

Dynamical quantum phase transitions (DQPTs), which refer to the criticality in time of a quantum many-body system, have attracted much theoretical and experimental research interest recently. Despite DQPTs are defined and signalled by the…

Strongly Correlated Electrons · Physics 2021-08-11 Wing Chi Yu , P. D. Sacramento , Yan Chao Li , Hai-Qing Lin

We study the Loschmidt echo for a system of electrons interacting through mean-field Coulomb forces. The electron gas is modeled by a self-consistent set of hydrodynamic equations. It is observed that the quantum fidelity drops abruptly…

Quantum Physics · Physics 2009-11-13 G. Manfredi , P. -A. Hervieux

We present a general dynamic finite-size scaling theory for the quantum dynamics after an abrupt quench, at both continuous and first-order quantum transitions. For continuous transitions, the scaling laws are naturally ruled by the…

Statistical Mechanics · Physics 2018-06-01 Andrea Pelissetto , Davide Rossini , Ettore Vicari

The quantum phase transitions provide a paradigm for studying collective quantum phenomena that are a result of competing non-commuting interactions. This paper will study the ground state properties and quantum critical dynamics of the…

Quantum Physics · Physics 2026-01-27 Rudraksh Sharma