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We present a systematic construction of effective Hamiltonians of periodically driven quantum systems. Because of an equivalence between the time dependence of a Hamiltonian and an interaction in its Floquet operator, flow equations, that…

Quantum Physics · Physics 2013-10-23 Albert Verdeny , Andreas Mielke , Florian Mintert

In this note we address the exact solutions of a time-dependent Hamiltonian composed by an oscillator-like interaction with both a frequency and a mass term that depend on time. The latter is achieved by constructing the appropriate point…

Quantum Physics · Physics 2020-02-26 Kevin Zelaya , Véronique Hussin

A condition on the Hamiltonian of a time-dependent quantum mechanical system is derived which, if satisfied, implies optimal adiabaticity (defined below). The condition is expressed in terms of the Hamiltonian and in terms of the evolution…

Quantum Physics · Physics 2013-02-07 R. MacKenzie , M. Pineault , L. Renaud-Desjardins

Quantum systems governed by time-dependent Hamiltonians pose significant challenges for the accurate computation of unitary time-evolution operators, which are essential for predicting quantum state dynamics. In this work, we introduce a…

Quantum Physics · Physics 2026-01-21 Antonio Guerra , Daniel Uzcategui-Contreras , Aldo Delgado , Esteban S. Gómez

Simulating physical systems has been an important application of classical and quantum computers. In this article we present an efficient classical algorithm for simulating time-dependent quantum mechanical Hamiltonians over constant…

Quantum Physics · Physics 2023-01-30 Reyhaneh Aghaei Saem , Ali Hamed Moosavian

In this paper, we present a proof-of-concept quantum algorithm for simulating time-dependent Hamiltonian evolution by reducing the problem to simulating a time-independent Hamiltonian in a larger space using a discrete clock Hamiltonian…

Quantum Physics · Physics 2025-07-28 Zecheng Li , Chunhao Wang

The sensitivity of the evolution of quantum uncertainties to the choice of the initial conditions is shown via a complex nonlinear Riccati equation leading to a reformulation of quantum dynamics. This sensitivity is demonstrated for systems…

Quantum Physics · Physics 2015-05-27 Hans Cruz , Dieter Schuch , Octavio Castaños , Oscar Rosas-Ortiz

A novel expansion of the evolution operator associated with a -- in general, time-dependent -- perturbed quantum Hamiltonian is presented. It is shown that it has a wide range of possible realizations that can be fitted according to…

Quantum Physics · Physics 2009-11-11 Paolo Aniello

Effective Hamiltonians governing the time evolution in a subspace of unstable states can be found using more or less accurate approximations. A convenient tool for deriving them is the evolution equation for a subspace of state space…

Quantum Physics · Physics 2014-09-11 K. Urbanowski

Given a quantum Hamiltonian and its evolution time, the corresponding unitary evolution operator can be constructed in many different ways, corresponding to different trajectories between the desired end-points. A choice among these…

Quantum Physics · Physics 2015-03-05 Apoorva Patel

We propose a solution to the problem of time for systems with a single global Hamiltonian constraint. Our solution stems from the observation that, for these theories, conventional gauge theory methods fail to capture the full classical…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Sean Gryb , Karim Thebault

The Hamiltonian of a quantum system governs the dynamics of the system via the Schrodinger equation. In this paper, the Hamiltonian is reconstructed in the Pauli basis using measurables on random states forming a time series dataset. The…

Quantum Physics · Physics 2023-05-10 Rishabh Gupta , Raja Selvarajan , Manas Sajjan , Raphael D. Levine , Sabre Kais

Recently, there has been an increasing interest in modelling and computation of physical systems with neural networks. Hamiltonian systems are an elegant and compact formalism in classical mechanics, where the dynamics is fully determined…

Numerical Analysis · Mathematics 2022-06-28 Elena Celledoni , Andrea Leone , Davide Murari , Brynjulf Owren

Hamiltonian mechanics describes the evolution of a system through its Hamiltonian. The Hamiltonian typically also represents the energy observable, a Noether-conserved quantity associated with the time-invariance of the law of evolution. In…

Quantum Physics · Physics 2024-03-29 Libo Jiang , Daniel R. Terno , Oscar Dahlsten

The most widely used approach for simulating the dynamics of time-dependent Hamiltonians via quantum computation depends on the quantum-classical hybrid variational quantum time evolution algorithm, in which ordinary differential equations…

Quantum Physics · Physics 2026-03-19 Minchen Qiao , Zi-Ming Li , Yu-xi Liu

We discuss a general and systematic method for obtaining effective Hamiltonians that describe different nonlinear optical processes. The method exploits the existence of a nonlinear deformation of the usual su(2) algebra that arises as the…

Quantum Physics · Physics 2007-05-23 A. B. Klimov , L. L. Sanchez-Soto , A. Navarro , E. C. Yustas

We present a recursive formula for the computation of the static effective Hamiltonian of a system under a fast-oscillating drive. Our analytical result is well-suited to symbolic calculations performed by a computer and can be implemented…

An exact invariant is derived for three-dimensional Hamiltonian systems of $N$ particles confined within a general velocity-independent potential. The invariant is found to contain a time-dependent function $f_{2}(t)$, embodying a solution…

Classical Physics · Physics 2023-08-08 Jürgen Struckmeier , Claus Riedel

We introduce an iterative method to search for time-optimal Hamiltonians that drive a quantum system between two arbitrary, and in general mixed, quantum states. The method is based on the idea of progressively improving the efficiency of…

Quantum Physics · Physics 2019-12-25 Francesco Campaioli , William Sloan , Kavan Modi , Felix Alexander Pollock

We study classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a probability distribution to the physical time, which is assumed to be discrete. - This is motivated by the ``timeless''…

General Relativity and Quantum Cosmology · Physics 2015-06-25 H. -T. Elze