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The description of an open quantum system's decay almost always requires several approximations as to remain tractable. Here, we first revisit the meaning, domain and seeming contradictions of a few of the most widely used of such…

Quantum Physics · Physics 2021-06-02 Juliane Klatt , Chahan Michael Kropf , Stefan Yoshi Buhmann

We propose a new variational quantum algorithm, which we refer to as TIMES-ADAPT, that prepares time-evolved states in a low-energy or symmetric subspace of a time-independent Hamiltonian on a quantum computer. Using a specially trained…

We present both, theory and an algorithm for solving time-harmonic wave problems in a general setting. The time-harmonic solutions will be achieved by computing time-periodic solutions of the original wave equations. Thus, an exact…

Analysis of PDEs · Mathematics 2011-05-23 Dirk Pauly , Tuomo Rossi

We propose a unified approach for different exponential perturbation techniques used in the treatment of time-dependent quantum mechanical problems, namely the Magnus expansion, the Floquet--Magnus expansion for periodic systems, the…

Numerical Analysis · Mathematics 2024-01-24 Ana Arnal , Fernando Casas , Cristina Chiralt

Quantum transition amplitudes are formulated for a model system with local internal time, using path integrals. The amplitudes are shown to be more regular near a turning point of internal time than could be expected based on existing…

General Relativity and Quantum Cosmology · Physics 2017-12-19 M. M. Amaral , Martin Bojowald

We investigate the relation between the invariant operators satisfying the quantum Liouville-von Neumann and the Heisenberg operators satisfying the Heisenberg equation. For time-dependent generalized oscillators we find the invariant…

Quantum Physics · Physics 2007-05-23 Sang Pyo Kim

We describe a method of construction of gauge-invariant operators (Dirac observables or ``evolving constants of motion'') from the knowledge of the eigenstates of the gauge generator in time-reparametrization invariant mechanical systems.…

General Relativity and Quantum Cosmology · Physics 2020-04-07 Leonardo Chataignier

In this paper we develop an analogue of Hamilton-Jacobi theory for the time-evolution operator of a quantum many-particle system. The theory offers a useful approach to develop approximations to the time-evolution operator, and also…

Statistical Mechanics · Physics 2019-08-07 Michael Vogl , Pontus Laurell , Aaron D. Barr , Gregory A. Fiete

In this work, new finite difference schemes are presented for dealing with the upper-convected time derivative in the context of the generalized Lie derivative. The upper-convected time derivative, which is usually encountered in the…

Numerical Analysis · Mathematics 2023-03-31 Debora O. Medeiros , Hirofumi Notsu , Cassio M. Oishi

In this paper, we consider the problem of controlling a dynamical system such that its trajectories satisfy a temporal logic property in a given amount of time. We focus on multi-affine systems and specifications given as syntactically…

Systems and Control · Computer Science 2012-03-27 Ebru Aydin Gol , Calin Belta

This paper considers the numerical treatment of the time-dependent Gross-Pitaevskii equation. In order to conserve the time invariants of the equation as accurately as possible, we propose a Crank-Nicolson-type time discretization that is…

Numerical Analysis · Mathematics 2021-10-20 Patrick Henning , Johan Wärnegård

In this review, we analyse different aspects concerning the possibility to separate a gravity-matter system into a part which lives close to a quasi-classical state and a "small" quantum subset. The considered approaches are all relying on…

General Relativity and Quantum Cosmology · Physics 2022-10-27 Giulia Maniccia , Mariaveronica De Angelis , Giovanni Montani

We present a number of new physical systems that may be addressed using methods of time dependent transformation. A recap of results available for two-state systems is given, with particular emphasis on the AC stark effect. We give some…

Quantum Physics · Physics 2023-06-05 Peter Morrison

The dilation method is a practical way to experimentally simulate non-Hermitian, especially $\cal PT$-symmetric quantum systems. However, the time-dependent dilation problem cannot be explicitly solved in general. In this paper, we present…

Quantum Physics · Physics 2022-06-20 Minyi Huang , Ray-Kuang Lee , Qing-hai Wang , Guo-Qiang Zhang , Junde Wu

The Rosenbrock-Krylov family of time integration schemes is an extension of Rosenbrock-W methods that employs a specific Krylov based approximation of the linear system solutions arising within each stage of the integrator. This work…

Numerical Analysis · Mathematics 2019-10-08 Paul Tranquilli , Ross Glandon , Adrian Sandu

Simulating Hamiltonian dynamics is one of the most fundamental and significant tasks for characterising quantum materials. Recently, a series of quantum algorithms employing block-encoding of Hamiltonians have succeeded in providing…

Quantum Physics · Physics 2023-01-18 Kaoru Mizuta

We develop the Euclidean time method of the variational quantum eigensolver for solving the generalized eigenvalue equation $A \ket{\phi_n} = \lambda_n B \ket{\phi_n}$, where $A$ and $B$ are hermitian operators, and $\ket{\phi_n}$ and…

Quantum Physics · Physics 2024-04-23 Mi-Ra Hwang , Eylee Jung , Museong Kim , DaeKil Park

The SWKB quantization condition is an exact quantization condition for the conventional shape-invariant potentials. On the other hand, this condition equation does not hold for other known solvable systems. The origin of the (non-)exactness…

Quantum Physics · Physics 2023-01-25 Yuta Nasuda , Nobuyuki Sawado

The dynamics of time-dependent coupled oscillator model for the charged particle motion subjected to a time-dependent external magnetic field is investigated. We used canonical transformation approach for the classical treatment of the…

Quantum Physics · Physics 2015-05-20 Salah Menouar , Mustapha Maamache , Jeong Ryeol Choi

We consider the formally determined inverse problem of recovering an unknown time-dependent potential function from the knowledge of the restriction of the solution of the wave equation to a small subset, subject to a single external…

Analysis of PDEs · Mathematics 2023-05-10 Ali Feizmohammadi , Yavar Kian