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Main Authors: Zhang, Xing-Yu, Chi, Runze, Liu, Yang, Wang, Lei
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2310.15759
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author Zhang, Xing-Yu
Chi, Runze
Liu, Yang
Wang, Lei
author_facet Zhang, Xing-Yu
Chi, Runze
Liu, Yang
Wang, Lei
contents Understanding the excitation spectrum in two-dimensional quantum many-body systems has long been a challenging task. We present an approach by introducing an excitation ansatz based on an infinite matrix product state (MPS) on a helix structure. With the canonical form of MPS states, we can accurately extract key properties such as energy, degeneracy, spectrum weight, and scaling behavior of low-energy excited states simultaneously. To validate the effectiveness of this method, we begin by applying it to the critical point of the transverse-field Ising model. The extracted scaling exponent of the energy gap closely aligns with the conformal bootstrap results. Subsequently, we apply this approach to the $J_1$-$J_2$ Heisenberg model on a square lattice. We discover that the degeneracy of lowest-energy excitations serves as a reliable metric for distinguishing different phases. The phase boundary identified by our method is consistent with some of the previous findings. The present method provides a promising avenue for studying the excitation spectrum of two-dimensional quantum many-body systems.
format Preprint
id arxiv_https___arxiv_org_abs_2310_15759
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle 2D excitation information by MPS method on infinite helixes
Zhang, Xing-Yu
Chi, Runze
Liu, Yang
Wang, Lei
Strongly Correlated Electrons
Understanding the excitation spectrum in two-dimensional quantum many-body systems has long been a challenging task. We present an approach by introducing an excitation ansatz based on an infinite matrix product state (MPS) on a helix structure. With the canonical form of MPS states, we can accurately extract key properties such as energy, degeneracy, spectrum weight, and scaling behavior of low-energy excited states simultaneously. To validate the effectiveness of this method, we begin by applying it to the critical point of the transverse-field Ising model. The extracted scaling exponent of the energy gap closely aligns with the conformal bootstrap results. Subsequently, we apply this approach to the $J_1$-$J_2$ Heisenberg model on a square lattice. We discover that the degeneracy of lowest-energy excitations serves as a reliable metric for distinguishing different phases. The phase boundary identified by our method is consistent with some of the previous findings. The present method provides a promising avenue for studying the excitation spectrum of two-dimensional quantum many-body systems.
title 2D excitation information by MPS method on infinite helixes
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2310.15759