English
Related papers

Related papers: A multi-state mapping approach to surface hopping

200 papers

Estimating physical properties of quantum states from measurements is one of the most fundamental tasks in quantum science. In this work, we identify conditions on states under which it is possible to infer the expectation values of all…

Quantum Physics · Physics 2024-05-01 Cambyse Rouzé , Daniel Stilck França

Surface hopping algorithms are popular tools to study dynamics of the quantum-classical mixed systems. In this paper, we propose a surface hopping algorithm in diabatic representations, based on time dependent perturbation theory and…

Numerical Analysis · Mathematics 2022-10-19 Di Fang , Jianfeng Lu

We introduce the multistate iterative qubit coupled cluster (MS-iQCC) method, a quantum-inspired algorithm that runs efficiently on classical hardware and is designed to predict both ground and excited electronic states of molecules.…

Chemical Physics · Physics 2026-01-05 Robert A. Lang , Shashank G. Mehendale , Ilya G. Ryabinkin , Artur F. Izmaylov

Accurate simulation the many-electronic nonadiabatic dynamics process at metal surfaces remains as a significant task. In this work, we present an orbital surface hopping (OSH) algorithm rigorously derived from the orbital quantum classical…

Chemical Physics · Physics 2025-11-24 Yong-Tao Ma , Rui-Hao Bi , Wenjie Dou

We introduce new multilevel methods for solving large-scale unconstrained optimization problems. Specifically, the philosophy of multilevel methods is applied to Newton-type methods that regularize the Newton sub-problem using second order…

Optimization and Control · Mathematics 2024-07-16 Nick Tsipinakis , Panos Parpas

It is well known that numerical simulations of high-speed reacting flows, in the framework of state-to-state formulations, are the most detailed but also often prohibitively computationally expensive. In this work, we start to investigate…

Fluid Dynamics · Physics 2024-06-19 Lorenzo Campoli , Elena Kustova , Polina Maltseva

A fundamental task in quantum information is to approximate a pure quantum state in terms of sparse states or, for a bipartite system, states of bounded Schmidt rank. The optimal deterministic approximation in each case is straightforward,…

Quantum Physics · Physics 2026-01-06 Aram W. Harrow , Angus Lowe , Freek Witteveen

We study the fair sampling properties of hybrid quantum-classical Markov chain Monte Carlo (MCMC) algorithms for combinatorial optimization problems with degenerate ground states. While quantum optimization heuristics such as quantum…

Quantum Physics · Physics 2025-12-17 Yuichiro Nakano , Keisuke Fujii

Recent studies highlight the effectiveness of flat minima in enhancing generalization, with sharpness-aware minimization (SAM) achieving state-of-the-art performance. Additionally, insights into the intrinsic geometry of the loss landscape…

Machine Learning · Computer Science 2025-06-10 Tuan Truong , Hoang-Phi Nguyen , Haocheng Luo , Tung Pham , Mehrtash Harandi , Dinh Phung , Trung Le

Variational algorithms for strongly correlated chemical and materials systems are one of the most promising applications of near-term quantum computers. We present an extension to the variational quantum eigensolver that approximates the…

Quantum Physics · Physics 2020-08-26 William J. Huggins , Joonho Lee , Unpil Baek , Bryan O'Gorman , K. Birgitta Whaley

The ground state nature of the Falicov-Kimball model with unconstrained hopping of electrons is investigated. We solve the eigenvalue problem in a pedagogical manner and give a complete account of the ground state energy both as a function…

Statistical Mechanics · Physics 2007-05-23 Oscar Bolina , Domingos H. U. Marchetti

This paper considers the problem of remote state estimation for Markov jump linear systems in the presence of uncertainty in the posterior mode probabilities. Such uncertainty may arise when the estimator receives noisy or incomplete…

Systems and Control · Electrical Eng. & Systems 2025-09-05 Ioannis Tzortzis , Themistoklis Charalambous , Charalambos D. Charalambous

A precise dynamical characterization of quantum impurity models with multiple interacting orbitals is challenging. In quantum Monte Carlo methods, this is embodied by sign problems. A dynamical sign problem makes it exponentially difficult…

Mesoscale and Nanoscale Physics · Physics 2024-07-02 Andre Erpenbeck , Thomas Blommel , Lei Zhang , Wei-Ting Lin , Guy Cohen , Emanuel Gull

There has long been interest to control the transfer of population between specified quantum states. Recent work has optimized the control law for closed system population transfer by using a gradient ascent pulse engineer- ing algorithm…

Quantum Physics · Physics 2010-04-28 Wei Cui , Zairong Xi , Yu Pan

Simulating electron-nucleus coupled dynamics poses a non-trivial challenge and an important problem in the investigation of ultrafast processes involving coupled electronic and vibrational dynamics. Because irreversibility of the system…

Chemical Physics · Physics 2019-04-11 Tatsushi Ikeda , Yoshitaka Tanimura

The symmetry-projected Hartree--Fock ansatz for the electronic structure problem can efficiently account for static correlation in molecules, yet it is often unable to describe dynamic correlation in a balanced manner. Here, we consider a…

Strongly Correlated Electrons · Physics 2015-06-17 Carlos A. Jiménez-Hoyos , R. Rodríguez-Guzmán , Gustavo E. Scuseria

We use matrix product techniques to investigate the performance of two algorithms for obtaining the ground state of a quantum many-body Hamiltonian $H = H_A + H_B$ in infinite systems. The first algorithm is a generalization of the quantum…

Strongly Correlated Electrons · Physics 2022-11-30 Ruoshui Wang , Timothy H. Hsieh , Guifre Vidal

Quantum systems coupled to (non-)Markovian environments attract increasing attention due to their peculiar physical properties. Exciting prospects such as unconventional non-equilibrium phases beyond the Mermin-Wagner limit, or the…

Quantum Physics · Physics 2025-09-10 Philipp Westhoff , Mattia Moroder , Ulrich Schollwöck , Sebastian Paeckel

We extend the class of SQP methods for equality constrained optimization to the setting of differentiable manifolds. The use of retractions and stratifications allows us to pull back the involved mappings to linear spaces. We study local…

Optimization and Control · Mathematics 2020-05-15 Anton Schiela , Julian Ortiz

The Markov Chain Monte Carlo method is at the heart of efficient approximation schemes for a wide range of problems in combinatorial enumeration and statistical physics. It is therefore very natural and important to determine whether…

Quantum Physics · Physics 2009-11-13 Pawel Wocjan , Anura Abeyesinghe