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In this note, we develop a framework to describe open quantum systems in the Heisenberg picture, i.e., via time evolving operator algebras. We point out the incompleteness of the previous proposals in this regard. We argue that a complete…

Quantum Physics · Physics 2020-12-01 Nachiket Karve , R. Loganayagam

The Lewis and Riesenfeld method has been investigated, by Ramos et al in Ref.[1], for quantum systems governed by time-dependent PT symmetric Hamiltonians and particularly where the quantum system is a particle submitted to action of a…

Quantum Physics · Physics 2020-03-18 Walid Koussa , Mustapha Maamache

James' effective Hamiltonian method has been extensively adopted to investigate largely detuned interacting quantum systems. This method is just corresponding to the second-order perturbation theory, and cannot be exploited to treat the…

Quantum Physics · Physics 2017-04-05 Wenjun Shao , Chunfeng Wu , Xun-Li Feng

In many scenarios of interest, a quantum system interacts with an unknown environment, necessitating the use of open quantum system methods to capture dissipative effects and environmental noise. With the long-term goal of developing a…

High Energy Physics - Theory · Physics 2025-03-26 Santiago Agui Salcedo , Thomas Colas , Enrico Pajer

The most realistic situations in quantum mechanics involve the interaction between two or more systems. In the most of reliable models, the form and structure of the interactions generate differential equations which are, in the most of…

Quantum Physics · Physics 2016-09-01 C. A. M. de Melo , B. M. Pimentel , J. A. Ramirez

Adaptive perturbation is a new method for perturbatively computing the eigenvalues and eigenstates of quantum mechanical Hamiltonians that are widely believed not to be solvable by such methods. The novel feature of adaptive perturbation…

High Energy Physics - Theory · Physics 2008-11-26 Marvin Weinstein

We classify combinatorial Dyson-Schwinger equations giving a Hopf subalgebra of the Hopf algebra of Feynman graphs of the considered Quantum Field Theory. We first treat single equations with an arbitrary number (eventually infinite) of…

Rings and Algebras · Mathematics 2011-12-13 Loïc Foissy

In quantum mechanics, the Schrieffer--Wolff (SW) transformation (also called quasi-degenerate perturbation theory) is known as an approximative method to reduce the dimension of the Hamiltonian. We present a geometric interpretation of the…

Quantum Physics · Physics 2026-04-01 Gergő Pintér , György Frank , Dániel Varjas , András Pályi

This work introduces the Schmidt quantum compressor, an innovative approach to quantum data compression that leverages the principles of Schmidt decomposition to encode quantum information efficiently. In contrast to traditional variational…

Quantum Physics · Physics 2025-08-06 Israel F. Araujo , Hyeondo Oh , Nayeli A. Rodríguez-Briones , Daniel K. Park

A new method of approximation scheme with potential application to a general interacting quantum system is presented. The method is non-perturbative, self- consistent, systematically improvable and uniformly applicable for arbitrary…

Quantum Physics · Physics 2008-06-13 Nabaghan Santi

The Wigner-von Neumann method, which was previously used for perturbing continuous Schr\"{o}dinger operators, is here applied to their discrete counterparts. In particular, we consider perturbations of arbitrary $T$-periodic Jacobi…

Functional Analysis · Mathematics 2016-06-03 Edmund Judge , Sergey Naboko , Ian Wood

We give a thorough analysis of the convergence properties of the configuration-interaction method as applied to parabolic quantum dots among other systems, including \emph{a priori} error estimates. The method converges slowly in general,…

Computational Physics · Physics 2013-05-29 Simen Kvaal

Successful applications of a conceptually novel setup of Quantum Field Theory, that accounts for all subtheories of the Standard Model (QED, Electroweak Interaction and Higgs, Yang-Mills and QCD) and beyond (Helicity 2), call for a…

High Energy Physics - Theory · Physics 2024-09-19 Karl-Henning Rehren , Lucas T. Cardoso , Christian Gass , José M. Gracia-Bondía , Bert Schroer , Joseph C. Várilly

A powerful method for calculating the eigenvalues of a Hamiltonian operator consists of converting the energy eigenvalue equation into a matrix equation by means of an appropriate basis set of functions. The convergence of the method can be…

Quantum Physics · Physics 2007-05-23 Paolo Amore , Alfredo Aranda , Francisco Fernandez , Hugh Jones

We consider a simple modification of the 1D-Laplacian where non-mixed interface conditions occur at the boundaries of a finite interval. It has recently been shown that Schr\"odinger operators having this form allow a new approach to the…

Mathematical Physics · Physics 2015-06-11 Andrea Mantile

(abridged)If the space-time is presupposed, the coordinate representation of the solutions $\psi(\vec x, t)$ of the Schroedinger equation of a quantum system containing one massive scalar particle has a {\it preferred status}. It is then…

Quantum Physics · Physics 2012-07-06 Luca Lusanna , Massimo Pauri

The eigenvalue problem for one-dimensional Schr\"{o}dinger equation with the rational potential is numerically solved by the operator method. We show that the operator method, applied for solving the Schr\"{o}dinger equation with the…

Quantum Physics · Physics 2007-05-23 Petr A. Khomyakov

Accurate solution of the many-electron problem including correlations remains intractable except for few-electron systems. Describing interacting electrons as a superposition of independent electron configurations results in an apparent…

Computational Physics · Physics 2024-02-20 J. C. Greer

We derive universal entanglement entropy and Schmidt eigenvalue behaviors for the eigenstates of two quantum chaotic systems coupled with a weak interaction. The progression from a lack of entanglement in the noninteracting limit to the…

Quantum Physics · Physics 2018-09-19 Steven Tomsovic , Arul Lakshminarayan , Shashi C. L. Srivastava , Arnd Bäcker

We propose a simple quantum algorithm for simulating highly oscillatory quantum dynamics, which does not require complicated quantum control logic for handling time-ordering operators. To our knowledge, this is the first quantum algorithm…

Quantum Physics · Physics 2022-04-20 Dong An , Di Fang , Lin Lin