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Related papers: On unitary time evolution out of equilibrium

200 papers

This colloquium gives an overview of recent theoretical and experimental progress in the area of nonequilibrium dynamics of isolated quantum systems. We particularly focus on quantum quenches: the temporal evolution following a sudden or…

Statistical Mechanics · Physics 2011-09-29 Anatoli Polkovnikov , Krishnendu Sengupta , Alessandro Silva , Mukund Vengalattore

We consider a spin-boson Hamiltonian which is generalized such that the Hamiltonians for the system ($\hat{H}_{\cal S}$) and the interaction with the environment ($\hat{H}_{\rm int}$) do not commute with each other. Considering a…

Quantum Physics · Physics 2015-03-19 Hoofar Daneshvar , G. W. F. Drake

A fundamental description of time can be consistent not only with the usual monotonic behavior but also with a periodic physical clock variable, coupled to the degrees of freedom of a system evolving in time. Generically, one would in fact…

Quantum Physics · Physics 2022-05-25 Martin Bojowald , Luiz Martinez , Garrett Wendel

We develop a resonance theory to describe the evolution of open systems with time-dependent dynamics. Our approach is based on piecewise constant Hamiltonians: we represent the evolution on each constant bit using a recently developed…

Mathematical Physics · Physics 2011-08-25 Marco Merkli , Shannon Starr

We study the unitary time evolution of a simple quantum Hamiltonian describing two harmonic oscillators coupled via a three-level system. The latter acts as an engine transferring energy from one oscillator to the other and is driven in a…

Quantum Physics · Physics 2015-04-01 Winny O'Kelly de Galway , Jan Naudts

A generic non-integrable (unitary) out-of-equilibrium quantum process, when interrogated across many times, is shown to yield the same statistics as an (non-unitary) equilibrated process. In particular, using the tools of quantum stochastic…

Quantum Physics · Physics 2023-07-18 Neil Dowling , Pedro Figueroa-Romero , Felix A. Pollock , Philipp Strasberg , Kavan Modi

Loop quantum cosmology was shown to interpolate between de Sitter and FLRW Universe phases through a bounce by including Euclidean and Lorentzian terms of the Hamiltonian constraint with weight one -that corresponding to classical General…

General Relativity and Quantum Cosmology · Physics 2025-04-01 Omar Gallegos , Tonatiuh Matos , Hugo A. Morales-Técotl

We study the time dependent transitions of quantum forced harmonic oscillator (QFHO) in noncommutative $\mathds{R}^{1,1}$ perturbatively to linear order in the noncommutativity $\theta$. We show that the Poisson distribution gets modified,…

High Energy Physics - Theory · Physics 2012-02-13 Nitin Chandra

A quantum field has been coupled to a space-time with accelerating expansion. Dynamical modes are destabilised successively at shorter material wavelengths as they metamorphose from oscillators to repellers. Due to degeneracy of energy…

General Relativity and Quantum Cosmology · Physics 2024-04-29 Philip Broadbridge , Sarah Becirevic , David Hoxley

The time-dependent probability density function of a system evolving towards a stationary state exhibits an oscillatory behavior if the eigenvalues of the corresponding evolution operator are complex. The frequencies \omega_n, with which…

Statistical Mechanics · Physics 2012-06-22 R. Salgado-Garcia

We study the time evolution and steady state of the charge current in a single-impurity Anderson model, using matrix product states techniques. A nonequilibrium situation is imposed by applying a bias voltage across one-dimensional…

Strongly Correlated Electrons · Physics 2013-07-31 Martin Nuss , Martin Ganahl , Hans Gerd Evertz , Enrico Arrigoni , Wolfgang von der Linden

The (Loschmidt) overlap between the state at different times after a quantum quench is attracting increasing interest, as it was recently shown that in the thermodynamic limit its logarithm per unit of length has a non-analytic behavior if…

Statistical Mechanics · Physics 2013-09-09 Maurizio Fagotti

We consider Deutsch's computational model of a quantum system evolving in a spacetime containing closed timelike curves. Although it is known that this model predicts non-linear and non-unitary evolutions of the system, we demonstrate that…

Quantum Physics · Physics 2010-05-12 Richard DeJonghe , Kimberly Frey , Tom Imbo

We consider the time evolution of a state in an isolated quantum spin lattice system with energy cumulants proportional to the number of the sites $L^d$. We compute the distribution of the eigenvalues of the time averaged state over a time…

Quantum Physics · Physics 2019-05-15 Maurizio Fagotti

Evolutions of local Hamiltonians in short times are expected to remain local and thus limited. In this paper, we validate this intuition by proving some limitations on short-time evolutions of local time-dependent Hamiltonians. We show that…

Quantum Physics · Physics 2022-06-29 Ali Hamed Moosavian , Seyed Sajad Kahani , Salman Beigi

We propose a new point of view regarding the problem of time in quantum mechanics, based on the idea of replacing the usual time operator $\mathbf{T}$ with a suitable real-valued function $T$ on the space of physical states. The proper…

This work discusses a variational approach to determining the time evolution operator. We directly see a glimpse of how a generalization of the quantum geometric tensor for unitary operators plays a central role in parameter evolution. We…

Quantum Physics · Physics 2025-04-15 Michael Vogl

We analize the relational quantum evolution of generally covariant systems in terms of Rovelli's evolving constants of motion and the generalized Heisenberg picture. In order to have a well defined evolution, and a consistent quantum…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Rodolfo Gambini , Rafael A. Porto

The concept of weak invariants has recently been introduced in the context of conserved quantities in finite-time processes in nonequilibrium quantum thermodynamics. A weak invariant itself has a time-dependent spectrum, but its expectation…

Quantum Physics · Physics 2020-06-11 Sumiyoshi Abe

We present a relational framework in which temporal structure is not fundamental but emerges from correlations within a globally stationary quantum state. Each subsystem includes an internal clock, and conditional states evolve effectively…

Quantum Physics · Physics 2025-12-19 Amir Hossein Ghasemi