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We propose a neural-network variational quantum algorithm to simulate the time evolution of quantum many-body systems. Based on a modified restricted Boltzmann machine (RBM) wavefunction ansatz, the proposed algorithm can be efficiently…

Quantum Physics · Physics 2021-05-12 Chee-Kong Lee , Pranay Patil , Shengyu Zhang , Chang-Yu Hsieh

We increase the efficiency of a recently proposed time integration scheme for time dependent quantum transport by using the Lanczos method for time evolution. We illustrate our modified scheme in terms of a simple one dimensional model. Our…

Mesoscale and Nanoscale Physics · Physics 2008-08-13 Claudio Verdozzi , Carl-Olof Almbladh

We present algorithmic improvements for fast and memory-efficient use of discrete spatial symmetries in Exact Diagonalization computations of quantum many-body systems. These techniques allow us to work flexibly in the reduced basis of…

Strongly Correlated Electrons · Physics 2018-10-05 Alexander Wietek , Andreas M. Läuchli

Quantum computing can provide speedups in solving many problems as the evolution of a quantum system is described by a unitary operator in an exponentially large Hilbert space. Such unitary operators change the phase of their eigenstates…

Quantum Physics · Physics 2024-01-23 Youle Wang , Lei Zhang , Zhan Yu , Xin Wang

We study the universal properties of the Lanczos algorithm applied to finite-size many-body quantum systems. Focusing on autocorrelation functions of local operators and on their infinite-time behaviour at finite size, we conjecture that in…

Quantum Physics · Physics 2026-02-16 Luca Capizzi , Leonardo Mazza , Sara Murciano

Quantum phase estimation plays a central role in quantum simulation as it enables the study of spectral properties of many-body quantum systems. Most variants of the phase estimation algorithm require the application of the global unitary…

The recursion method, which solves coupled Heisenberg equations in a Lanczos operator basis, has recently emerged as a powerful nonperturbative tool for computing dynamical correlation functions in strongly correlated two- and…

Strongly Correlated Electrons · Physics 2026-04-29 Ilya Shirokov , Viacheslav Khrushchev , Filipp Uskov , Ivan Dudinets , Igor Ermakov , Oleg Lychkovskiy

Designing effective quantum circuits remains a central challenge in quantum computing, as circuit structure strongly influences expressivity, trainability, and hardware feasibility. Current approaches, whether using manually designed…

Neural and Evolutionary Computing · Computer Science 2026-02-04 Devroop Kar , Daniel Krutz , Travis Desell

We present a new algorithm that computes eigenvalues and eigenvectors of a Hermitian positive definite matrix while solving a linear system of equations with Conjugate Gradient (CG). Traditionally, all the CG iteration vectors could be…

High Energy Physics - Lattice · Physics 2011-10-12 Andreas Stathopoulos , Kostas Orginos

Certain aspects of some unitary quantum systems are well-described by evolution via a non-Hermitian effective Hamiltonian, as in the Wigner-Weisskopf theory for spontaneous decay. Conversely, any non-Hermitian Hamiltonian evolution can be…

High Energy Physics - Lattice · Physics 2021-12-01 Jay Hubisz , Bharath Sambasivam , Judah Unmuth-Yockey

We demonstrate how machine learning is able to model experiments in quantum physics. Quantum entanglement is a cornerstone for upcoming quantum technologies such as quantum computation and quantum cryptography. Of particular interest are…

Machine Learning · Computer Science 2022-07-04 Thomas Adler , Manuel Erhard , Mario Krenn , Johannes Brandstetter , Johannes Kofler , Sepp Hochreiter

In order to achieve fault-tolerant quantum computation, we need to repeat the following sequence of four steps: First, perform 1 or 2 qubit quantum gates (in parallel if possible). Second, do a syndrome measurement on a subset of the…

Quantum Physics · Physics 2024-12-11 Harry Buhrman , Marten Folkertsma , Bruno Loff , Niels M. P. Neumann

Lattice studies of spontaneous supersymmetry breaking suffer from a sign problem that in principle can be evaded through novel methods enabled by quantum computing. Focusing on lower-dimensional lattice systems with more modest resource…

High Energy Physics - Lattice · Physics 2024-10-16 David Schaich , Christopher Culver

Near term quantum computers with a high quantity (around 50) and quality (around 0.995 fidelity for two-qubit gates) of qubits will approximately sample from certain probability distributions beyond the capabilities of known classical…

Quantum Physics · Physics 2018-01-23 Sergio Boixo , Sergei V. Isakov , Vadim N. Smelyanskiy , Hartmut Neven

We introduce a multi-modal, multi-level quantum complex exponential least squares (MM-QCELS) method to simultaneously estimate multiple eigenvalues of a quantum Hamiltonian on early fault-tolerant quantum computers. Our theoretical analysis…

Quantum Physics · Physics 2023-10-18 Zhiyan Ding , Lin Lin

The theory of quantum algorithms promises unprecedented benefits of harnessing the laws of quantum mechanics for solving certain computational problems. A persistent obstacle to using such algorithms for solving a wide range of real-world…

Quantum simulators have made a remarkable progress towards exploring the dynamics of many-body systems, many of which offer a formidable challenge to both theoretical and numerical methods. While state-of-the-art quantum simulators are in…

Digital quantum computers provide a computational framework for solving the Schr\"{o}dinger equation for a variety of many-particle systems. Quantum computing algorithms for the quantum simulation of these systems have recently witnessed…

Quantum Physics · Physics 2022-03-21 Mario Motta , Julia Rice

The simulation of many-body open quantum systems is key to solving numerous outstanding problems in physics, chemistry, material science, and in the development of quantum technologies. Near-term quantum computers may bring considerable…

Quantum Physics · Physics 2025-02-05 Sara Santos , Xinyu Song , Vincenzo Savona

Quantum computers hold promise to circumvent the limitations of conventional computing for difficult molecular problems. However, the accumulation of quantum logic errors on real devices represents a major challenge, particularly in the…

Chemical Physics · Physics 2021-11-17 Michael A. Jones , Harish J. Vallury , Charles D. Hill , Lloyd C. L. Hollenberg