Re-anchoring Quantum Monte Carlo with Tensor-Train Sketching

Fuente: arXiv
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Autori principali: Yu, Ziang, Zhang, Shiwei, Khoo, Yuehaw
Natura: Preprint
Pubblicazione: 2024
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author Yu, Ziang
Zhang, Shiwei
Khoo, Yuehaw
author_facet Yu, Ziang
Zhang, Shiwei
Khoo, Yuehaw
contents We propose a novel algorithm for calculating the ground-state energy of quantum many-body systems by combining auxiliary-field quantum Monte Carlo (AFQMC) with tensor-train sketching. In AFQMC, a good trial wavefunction to guide the random walk is crucial for improving the sampling efficiency and controlling the sign problem. Our proposed method iterates between determining a new trial wavefunction in the form of a tensor train, derived from the current walkers, and using this updated trial wavefunction to anchor the next phase of AFQMC. Numerical results demonstrate that the algorithm is highly accurate for large spin systems. The overlap between the estimated trial wavefunction and the ground-state wavefunction also achieves high fidelity. We additionally provide a convergence analysis, highlighting how an effective trial wavefunction can reduce the variance in the AFQMC energy estimation. From a complementary perspective, our algorithm also extends the reach of tensor-train methods for studying quantum many-body systems.
format Preprint
id arxiv_https___arxiv_org_abs_2411_07194
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Re-anchoring Quantum Monte Carlo with Tensor-Train Sketching
Yu, Ziang
Zhang, Shiwei
Khoo, Yuehaw
Numerical Analysis
Computational Physics
15A69, 62G07, 65C05
We propose a novel algorithm for calculating the ground-state energy of quantum many-body systems by combining auxiliary-field quantum Monte Carlo (AFQMC) with tensor-train sketching. In AFQMC, a good trial wavefunction to guide the random walk is crucial for improving the sampling efficiency and controlling the sign problem. Our proposed method iterates between determining a new trial wavefunction in the form of a tensor train, derived from the current walkers, and using this updated trial wavefunction to anchor the next phase of AFQMC. Numerical results demonstrate that the algorithm is highly accurate for large spin systems. The overlap between the estimated trial wavefunction and the ground-state wavefunction also achieves high fidelity. We additionally provide a convergence analysis, highlighting how an effective trial wavefunction can reduce the variance in the AFQMC energy estimation. From a complementary perspective, our algorithm also extends the reach of tensor-train methods for studying quantum many-body systems.
title Re-anchoring Quantum Monte Carlo with Tensor-Train Sketching
topic Numerical Analysis
Computational Physics
15A69, 62G07, 65C05
url https://arxiv.org/abs/2411.07194