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Simulating quantum many-body dynamics is important both for fundamental understanding of physics and practical applications for quantum information processing. Therefore, classical simulation methods have been developed so far.…

Quantum Physics · Physics 2023-04-26 Yoshiaki Kawase , Keisuke Fujii

We consider the time discretization based on Lie-Trotter splitting, for the nonlinear Schrodinger equation, in the semi-classical limit, with initial data under the form of WKB states. We show that both the exact and the numerical solutions…

Numerical Analysis · Mathematics 2020-12-16 Rémi Carles , Clément Gallo

Nonequilibrium time evolution of large quantum systems is a strong candidate for quantum advantage. Variational quantum algorithms have been put forward for this task, but their quantum optimization routines suffer from trainability and…

Quantum Physics · Physics 2024-07-12 Refik Mansuroglu , Felix Fischer , Michael J. Hartmann

Hamiltonian simulation represents an important module in a large class of quantum algorithms and simulations such as quantum machine learning, quantum linear algebra methods, and modeling for physics, material science and chemistry. One of…

Quantum Physics · Physics 2023-05-30 Albert T. Schmitz , Nicolas P. D. Sawaya , Sonika Johri , A. Y. Matsuura

The cavity method is a well established technique for solving classical spin models on sparse random graphs (mean-field models with finite connectivity). Laumann et al. [arXiv:0706.4391] proposed recently an extension of this method to…

Statistical Mechanics · Physics 2009-11-13 Florent Krzakala , Alberto Rosso , Guilhem Semerjian , Francesco Zamponi

We present a novel, computationally efficient approach to accelerate quantum optimal control calculations of large multi-qubit systems used in a variety of quantum computing applications. By leveraging the intrinsic symmetry of finite…

Quantum Physics · Physics 2023-10-05 Xian Wang , Mahmut Sait Okyay , Anshuman Kumar , Bryan M. Wong

Quantum computers can efficiently simulate many-body systems. As a widely used Hamiltonian simulation tool, the Trotter-Suzuki scheme splits the evolution into the number of Trotter steps $N$ and approximates the evolution of each step by a…

Quantum Physics · Physics 2019-01-23 Suguru Endo , Qi Zhao , Ying Li , Simon Benjamin , Xiao Yuan

We introduce a self-consistent mean-field quantum optimization algorithm that approximates the ground state of classical Ising Hamiltonians. The algorithm decomposes the problem into independent subproblems and treats the interactions…

Quantum Physics · Physics 2026-03-11 Maxime Dupont , Bhuvanesh Sundar , Meenambika Gowrishankar

In the path integral formulation of the partition function of quantum spin models, most current treatments employ the so-called static approximation to simplify the process of summing over all possible paths. Although sufficient for…

Statistical Mechanics · Physics 2018-02-27 Yang Wei Koh

It is well-known that time-dependent Schr\"{o}dinger equation can only be exactly solvable in very rare cases, even for two-level quantum systems. Therefore, finding exact quantum dynamics under time-dependent Hamiltonian is not only of…

Quantum Physics · Physics 2024-12-17 Zhi-Cheng He , Yi-Xuan Wu , Zheng-Yuan Xue

We establish an efficient approximation algorithm for the partition functions of a class of quantum spin systems at low temperature, which can be viewed as stable quantum perturbations of classical spin systems. Our algorithm is based on…

Quantum Physics · Physics 2023-10-25 Tyler Helmuth , Ryan L. Mann

Motivated by the prospect of constraining microscopic models, we calculate the exact one-loop corrected de Sitter entropy (the logarithm of the sphere partition function) for every effective field theory of quantum gravity, with particles…

High Energy Physics - Theory · Physics 2022-02-22 Dionysios Anninos , Frederik Denef , Y. T. Albert Law , Zimo Sun

How to accurately solve time-dependent Schr\"odinger equation is an interesting and important problem. Here, we propose a novel method to obtain the exact Floquet solutions of the Schr\"odinger equation for periodically driven systems by…

Quantum Physics · Physics 2022-02-04 Xiao-Bo Yan

Quantum simulation is a foundational application for quantum computers, projected to offer insights into complex quantum systems beyond the reach of classical computation. However, with the exception of Trotter-based methods, which suffer…

Quantum Physics · Physics 2026-02-10 Amir Kalev , Itay Hen

Semidefinite programming is a powerful tool in the design and analysis of approximation algorithms for combinatorial optimization problems. In particular, the random hyperplane rounding method of Goemans and Williamson has been extensively…

Data Structures and Algorithms · Computer Science 2019-10-22 Sepehr Abbasi-Zadeh , Nikhil Bansal , Guru Guruganesh , Aleksandar Nikolov , Roy Schwartz , Mohit Singh

The exact dynamics of a system coupled to an environment can be described by an integro-differential stochastic equation of its reduced density. The influence of the environment is incorporated through a mean-field which is both stochastic…

Quantum Physics · Physics 2009-11-13 Denis Lacroix

Finding the ground state of a quantum mechanical system can be formulated as an optimal control problem. In this formulation, the drift of the optimally controlled process is chosen to match the distribution of paths in the Feynman--Kac…

Quantum Physics · Physics 2020-06-17 Ariel Barr , Willem Gispen , Austen Lamacraft

An approach is proposed to improve the efficiency of fourth-order algorithms for numerical integration of the equations of motion in molecular dynamics simulations. The approach is based on an extension of the decomposition scheme by…

Statistical Mechanics · Physics 2009-11-07 Igor Omelyan , Ihor Mryglod , Reinhard Folk

We establish tight connections between entanglement entropy and the approximation error in Trotter-Suzuki product formulas for Hamiltonian simulation. Product formulas remain the workhorse of quantum simulation on near-term devices, yet…

Quantum Physics · Physics 2026-02-03 Prateek P. Kulkarni

We present a new simple method for rounding a semidefinite programming relaxation of a constraint satisfaction problem. We apply it to the problem of approximate angular synchronization. Specifically, we are given directed distances on a…

Data Structures and Algorithms · Computer Science 2018-12-11 Kevin L. Chang , Alantha Newman