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Quantum computers open the possibility of performing real-time calculations for quantum field theory scattering processes. We propose to use an index averaging the absolute value of the difference between the accurately calculated Trotter…

High Energy Physics - Lattice · Physics 2021-10-18 Erik Gustafson , Patrick Dreher , Zheyue Hang , Yannick Meurice

Trotter approximation in conjunction with Quantum Phase Estimation can be used to extract eigen-energies of a many-body Hamiltonian on a quantum computer. There were several ways proposed to assess the quality of this approximation based on…

Smoothing is a technique that estimates the state of a system using measurement information both prior and posterior to the estimation time. Two notable examples of this technique are the Rauch-Tung-Striebel and Mayne-Fraser-Potter…

Quantum Physics · Physics 2021-09-24 Kiarn T. Laverick

We show how the highly accurate and efficient Constant Perturbation (CP) technique for steady-state Schr\"odinger problems can be used in the solution of time-dependent Schr\"odinger problems with explicitly time-dependent Hamiltonians,…

Numerical Analysis · Mathematics 2014-06-24 Veerle Ledoux , Marnix Van Daele

Herein, we propose a novel strategy for implementing a direct readout of the symmetric characteristic function of the quantum states of quantum fields without the involvement of idealized measurements, an aspect that has always been deemed…

Quantum Physics · Physics 2023-10-23 Zehua Tian , Jiliang Jing , Jiangfeng Du

The Schr\"odinger eigenvalue problem is solved with the imaginary time propagation technique. The separability of the Hamiltonian makes the problem suitable for the application of splitting methods. High order fractional time steps of order…

Numerical Analysis · Mathematics 2015-06-15 Philipp Bader , Sergio Blanes , Fernando Casas

The present contribution is based on the assumption that the probabilistic character of quantum mechanics does not originate from uncertainties caused by the process of measurement or observation, but rather reflects the presence of…

General Physics · Physics 2009-12-18 L. Fritsche , M. Haugk

We give the first deterministic fully polynomial-time approximation scheme (FPTAS) for computing the partition function of a two-state spin system on an arbitrary graph, when the parameters of the system satisfy the uniqueness condition on…

Data Structures and Algorithms · Computer Science 2011-11-09 Liang Li , Pinyan Lu , Yitong Yin

Comprehending the dynamical behaviour of quantum systems driven by time-varying Hamiltonians is particularly difficult. Systems with as little as two energy levels are not yet fully understood as the usual methods including diagonalisation…

Quantum Physics · Physics 2020-10-13 Pierre-Louis Giscard , Christian Bonhomme

In the present paper we consider the semiclassical magnetic Schr\"odinger equation, which describes the dynamics of charged particles under the influence of a electro-magnetic field. The solution of the time-dependent Schr\"odinger equation…

Numerical Analysis · Mathematics 2025-04-07 Malik Scheifinger , Kurt Busch , Marlis Hochbruck , Caroline Lasser

The quantum break-time of a system is the time-scale after which its true quantum evolution departs from the classical mean field evolution. For capturing it, a quantum resolution of the classical background - e.g., in terms of a coherent…

High Energy Physics - Theory · Physics 2017-11-01 Gia Dvali , Cesar Gomez , Sebastian Zell

We show that the time-dependent variational principle provides a unifying framework for time-evolution methods and optimisation methods in the context of matrix product states. In particular, we introduce a new integration scheme for…

Quantum Physics · Physics 2016-10-19 Jutho Haegeman , Christian Lubich , Ivan Oseledets , Bart Vandereycken , Frank Verstraete

Simulating the real-time dynamics of quantum field theories (QFTs) is one of the most promising applications of quantum simulators. Regularizing a bosonic QFT for quantum simulation purposes typically involves a truncation in Hilbert space…

Quantum Physics · Physics 2025-09-01 Gabriele Calliari , Marco Di Liberto , Hannes Pichler , Torsten V. Zache

Simulating the dynamic evolutions of physical and molecular systems in a quantum computer is of fundamental interest in many applications. Its implementation requires efficient quantum simulation algorithms. The Lie-Trotter-Suzuki…

Quantum Physics · Physics 2022-11-15 Yue Yu , Yulin Chi , Chonghao Zhai , Jieshan Huang , Qihuang Gong , Jianwei Wang

The purpose of this work is the development of space-time discretization schemes for phase-field optimal control problems. First, a time discretization of the forward problem is derived using a discontinuous Galerkin formulation. Here, a…

Optimization and Control · Mathematics 2022-03-24 Denis Khimin , Marc C. Steinbach , Thomas Wick

We propose a hybrid approach to simulate quantum many body dynamics by combining Trotter based quantum algorithm with classical dynamic mode decomposition. The interest often lies in estimating observables rather than explicitly obtaining…

Quantum Physics · Physics 2023-07-31 Niladri Gomes , Jia Yin , Siyuan Niu , Chao Yang , Wibe Albert de Jong

Quantum annealing offers a promising strategy for solving complex optimization problems by encoding the solution into the ground state of a problem Hamiltonian. While most implementations rely on spin-$1/2$ systems, we explore the…

Quantum Physics · Physics 2026-05-12 M. Haider Akbar , Özgür E. Müstecaplıoğlu

Toward scalable quantum computing, the control of quantum systems needs to be robust against both coherent errors induced by parametric uncertainties and incoherent errors induced by environmental decoherence. This poses significant…

Quantum Physics · Physics 2025-07-11 Yidian Fan , Re-Bing Wu

An optimal control problem related to the probability of transition between stable states for a thermally driven Ginzburg-Landau equation is considered. The value function for the optimal control problem with a spatial discretization is…

Optimization and Control · Mathematics 2008-09-11 Mattias Sandberg

The reduced dynamics of a central spin coupled to a bath of N spin-1/2 particles arranged in a spin star configuration is investigated. The exact time evolution of the reduced density operator is derived, and an analytical solution is…

Quantum Physics · Physics 2007-05-23 Heinz-Peter Breuer , Daniel Burgarth , Francesco Petruccione
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