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We study the elliptic spin-1/2 Kondo model (spin-1/2 fermions in one dimension with fully anisotropic contact interactions with a magnetic impurity) in the light of mappings to bosonic systems using the fermion-boson correspondence and…

Strongly Correlated Electrons · Physics 2015-05-27 Sol H. Jacobsen , P. D. Jarvis

An efficient algorithm for time propagation of the time-dependent Kohn-Sham equations is presented. The algorithm is based on dividing the Hamiltonian into small time steps and assuming that it is constant over these steps. This allows for…

Computational Physics · Physics 2014-12-03 J. K. Dewhurst , K. Krieger , S. Sharma , E. K. U. Gross

In this work we propose an approach for implementing time-evolution of a quantum system using product formulas. The quantum algorithms we develop have provably better scaling (in terms of gate complexity and circuit depth) than a naive…

A discussion is given of the quantisation of a physical system with finite degrees of freedom subject to a Hamiltonian constraint by treating time as a constrained classical variable interacting with an unconstrained quantum state. This…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Charles Wang

We consider a non-Hermitian Hamiltonian in order to effectively describe a two-level system coupled to a generic dissipative environment. The total Hamiltonian of the model is obtained by adding a general anti-Hermitian part, depending on…

Quantum Physics · Physics 2013-10-25 Alessandro Sergi , Konstantin G. Zloshchastiev

We consider quantum many-body systems evolving under a time-independent Hamiltonian $H$ from a nonequilibrium initial state at time $t=0$ towards a close-to-equilibrium state at time $t=\tau$. Subsequently, this state is slightly perturbed…

Statistical Mechanics · Physics 2020-05-27 Lennart Dabelow , Peter Reimann

Explicit formulas expressing the solution to non-autonomous differential equations are of great importance in many application domains such as control theory or numerical operator splitting. In particular, intrinsic formulas allowing to…

Classical Analysis and ODEs · Mathematics 2023-03-13 Karine Beauchard , Jérémy Le Borgne , Frédéric Marbach

Generalized Gibbs ensembles have been used as powerful tools to describe the steady state of integrable many-particle quantum systems after a sudden change of the Hamiltonian. Here we demonstrate numerically, that they can be used for a…

Strongly Correlated Electrons · Physics 2018-05-02 Florian Lange , Zala Lenarčič , Achim Rosch

A chirped parametrically driven discrete nonlinear Schrodinger equation is discussed. It is shown that the system allows two resonant excitation mechanisms, i.e., successive two-level transitions (ladder climbing) or a continuous…

Quantum Physics · Physics 2019-08-09 Tsafrir Armon , Lazar Friedland

We examine the physical manifestations of exceptional points and passage times in a two-level system which is subjected to quantum measurements and which admits a non-Hermitian description. Using an effective Hamiltonian acting in the…

Quantum Physics · Physics 2015-06-12 A. Thilagam

We consider an open quantum system in $M_{d}(\mathbb{C})$ governed by quasiperiodic Hamiltonian with rationally independent frequencies and under assumption of Lyapunov-Perron reducibility of associated Schroedinger equation. We construct…

Mathematical Physics · Physics 2022-03-01 Krzysztof Szczygielski

We present a systematic derivation of the Heisenberg evolution of a trilinear bosonic Hamiltonian system in presence of a strong drive beyond the standard approximation of a classical, undepleted driving field. We employ a perturbative…

Quantum Physics · Physics 2026-04-01 Hanzhong Zhang , Avi Pe'er

In a classical scattering problem, the classical eikonal is defined as the generator of the canonical transformation that maps in-states to out-states. It can be regarded as the classical limit of the log of the quantum S-matrix. In a…

High Energy Physics - Theory · Physics 2025-01-28 Joon-Hwi Kim , Jung-Wook Kim , Sungsoo Kim , Sangmin Lee

We prove that the entanglement entropy of any pure initial state of a bipartite bosonic quantum system grows linearly in time with respect to the dynamics induced by any unstable quadratic Hamiltonian. The growth rate does not depend on the…

Quantum Physics · Physics 2022-01-19 Giacomo De Palma , Lucas Hackl

Recently a Hamiltonian formulation for the evolution of the universe dominated by multiple oscillatory scalar fields was developed by the present author and was applied to the investigation of the evolution of cosmological perturbations on…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Takashi Hamazaki

Our main goal in this paper is to extend to any system of coupled quadratic Hamiltonians some properties known for systems of quantum harmonic oscillators related with the Brownian Quantum Motion model. In a first part we get a rather…

Mathematical Physics · Physics 2012-11-19 Didier Robert

Dissipation in mechanics, optics, acoustics, and electronic circuits is nowadays recognized to be not always detrimental but can be exploited to achieve non-Hermitian topological phases or properties with functionalities for potential…

Mesoscale and Nanoscale Physics · Physics 2023-11-13 Tao Yu , Ji Zou , Bowen Zeng , J. W. Rao , Ke Xia

We introduce a framework for designing Hamiltonian engineering pulse sequences that systematically accounts for the effects of higher-order contributions to the Floquet-Magnus expansion. Our techniques result in simple, intuitive decoupling…

Quantum Physics · Physics 2024-01-15 Matthew Tyler , Hengyun Zhou , Leigh S. Martin , Nathaniel Leitao , Mikhail D. Lukin

It is shown that there exists a possibility of amplification of amplitudes of quantum pion modes with low momenta in the late time of chiral phase transition by using the Gaussian wave functional approximation in the O(4) linear sigma…

High Energy Physics - Phenomenology · Physics 2009-11-10 K. Watanabe , Y. Tsue , S. Nishiyama

We introduce a scalable variational method for simulating the dynamics of interacting open quantum bosonic systems deep in the quantum regime. The method is based on a multi-dimensional Wigner phase-space representation and employs a…

Quantum Physics · Physics 2025-07-21 Jacopo Tosca , Francesco Carnazza , Luca Giacomelli , Cristiano Ciuti