中国物理B ›› 2022, Vol. 31 ›› Issue (5): 57501-057501.doi: 10.1088/1674-1056/ac5987

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Dynamical signatures of the one-dimensional deconfined quantum critical point

Ning Xi(西宁) and Rong Yu(俞榕)   

  1. Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, China
  • 收稿日期:2021-12-29 修回日期:2022-02-26 出版日期:2022-05-14 发布日期:2022-04-29
  • 通讯作者: Rong Yu,E-mail:rong.yu@ruc.edu.cn E-mail:rong.yu@ruc.edu.cn
  • 基金资助:
    Project supported by the National Science Foundation of China (Grant No.12174441),the Fundamental Research Funds for the Central Universities,China,and the Research Funds of Remnin University of China (Grant No.18XNLG24).

Dynamical signatures of the one-dimensional deconfined quantum critical point

Ning Xi(西宁) and Rong Yu(俞榕)   

  1. Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Renmin University of China, Beijing 100872, China
  • Received:2021-12-29 Revised:2022-02-26 Online:2022-05-14 Published:2022-04-29
  • Contact: Rong Yu,E-mail:rong.yu@ruc.edu.cn E-mail:rong.yu@ruc.edu.cn
  • About author:2022-3-2
  • Supported by:
    Project supported by the National Science Foundation of China (Grant No.12174441),the Fundamental Research Funds for the Central Universities,China,and the Research Funds of Remnin University of China (Grant No.18XNLG24).

摘要: We study the critical scaling and dynamical signatures of fractionalized excitations at two different deconfined quantum critical points (DQCPs) in an S = 1/2 spin chain using the time evolution of infinite matrix product states. The scaling of the correlation functions and the dispersion of the conserved current correlations explicitly show the emergence of enhanced continuous symmetries at these DQCPs. The dynamical structure factors in several different channels reveal the development of deconfined fractionalized excitations at the DQCPs. Furthermore, we find an effective spin-charge separation at the DQCP between the ferromagnetic (FM) and valence bond solid (VBS) phases, and identify two continua associated with different types of fractionalized excitations at the DQCP between the X-direction and Z-direction FM phases. Our findings not only provide direct evidence for the DQCP in one dimension but also shed light on exploring the DQCP in higher dimensions.

关键词: one-dimensional antiferromagnetism, spin frustration, deconfined quantum critical point, spin dynamics, infinite time-evolving block decimation

Abstract: We study the critical scaling and dynamical signatures of fractionalized excitations at two different deconfined quantum critical points (DQCPs) in an S = 1/2 spin chain using the time evolution of infinite matrix product states. The scaling of the correlation functions and the dispersion of the conserved current correlations explicitly show the emergence of enhanced continuous symmetries at these DQCPs. The dynamical structure factors in several different channels reveal the development of deconfined fractionalized excitations at the DQCPs. Furthermore, we find an effective spin-charge separation at the DQCP between the ferromagnetic (FM) and valence bond solid (VBS) phases, and identify two continua associated with different types of fractionalized excitations at the DQCP between the X-direction and Z-direction FM phases. Our findings not only provide direct evidence for the DQCP in one dimension but also shed light on exploring the DQCP in higher dimensions.

Key words: one-dimensional antiferromagnetism, spin frustration, deconfined quantum critical point, spin dynamics, infinite time-evolving block decimation

中图分类号:  (Quantum spin liquids, valence bond phases and related phenomena)

  • 75.10.Kt
75.40.Gb (Dynamic properties?)