中国物理B ›› 2023, Vol. 32 ›› Issue (10): 107308-107308.doi: 10.1088/1674-1056/acea6c

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Melting of electronic/excitonic crystals in 2D semiconductor moiré patterns: A perspective from the Lindemann criterion

Jiyong Zhou(周纪勇)1, Jianju Tang(唐剑炬)1, and Hongyi Yu(俞弘毅)1,2,†   

  1. 1 Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing&School of Physics and Astronomy, Sun Yat-Sen University(Zhuhai Campus), Zhuhai 519082, China;
    2 State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China
  • 收稿日期:2023-06-04 修回日期:2023-07-12 接受日期:2023-07-26 出版日期:2023-09-21 发布日期:2023-09-22
  • 通讯作者: Hongyi Yu E-mail:yuhy33@mail.sysu.edu.cn
  • 基金资助:
    H.Y. acknowledges support by the National Natural Science Foundation of China (Grant No. 12274477) and the Department of Science and Technology of Guangdong Province of China (Grant No. 2019QN01X061).

Melting of electronic/excitonic crystals in 2D semiconductor moiré patterns: A perspective from the Lindemann criterion

Jiyong Zhou(周纪勇)1, Jianju Tang(唐剑炬)1, and Hongyi Yu(俞弘毅)1,2,†   

  1. 1 Guangdong Provincial Key Laboratory of Quantum Metrology and Sensing&School of Physics and Astronomy, Sun Yat-Sen University(Zhuhai Campus), Zhuhai 519082, China;
    2 State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China
  • Received:2023-06-04 Revised:2023-07-12 Accepted:2023-07-26 Online:2023-09-21 Published:2023-09-22
  • Contact: Hongyi Yu E-mail:yuhy33@mail.sysu.edu.cn
  • Supported by:
    H.Y. acknowledges support by the National Natural Science Foundation of China (Grant No. 12274477) and the Department of Science and Technology of Guangdong Province of China (Grant No. 2019QN01X061).

摘要: Using the Lindemann criterion, we analyzed the quantum and thermal melting of electronic/excitonic crystals recently discovered in two-dimensional (2D) semiconductor moiré patterns. We show that the finite 2D screening of the atomically thin material can suppress (enhance) the inter-site Coulomb (dipolar) interaction strength, thus inhibits (facilitates) the formation of the electronic (excitonic) crystal. Meanwhile, a strong enough moiré confinement is found to be essential for realizing the crystal phase with a wavelength near 10 nm or shorter. From the calculated Lindemann ratio which quantifies the fluctuation of the site displacement, we estimate that the crystal will melt into a liquid above a critical temperature ranging from several tens Kelvin to above 100 K (depending on the system parameters).

关键词: moiré, pattern, transition metal dichalcogenides, electronic crystal, excitonic crystal, Lindemann criterion

Abstract: Using the Lindemann criterion, we analyzed the quantum and thermal melting of electronic/excitonic crystals recently discovered in two-dimensional (2D) semiconductor moiré patterns. We show that the finite 2D screening of the atomically thin material can suppress (enhance) the inter-site Coulomb (dipolar) interaction strength, thus inhibits (facilitates) the formation of the electronic (excitonic) crystal. Meanwhile, a strong enough moiré confinement is found to be essential for realizing the crystal phase with a wavelength near 10 nm or shorter. From the calculated Lindemann ratio which quantifies the fluctuation of the site displacement, we estimate that the crystal will melt into a liquid above a critical temperature ranging from several tens Kelvin to above 100 K (depending on the system parameters).

Key words: moiré, pattern, transition metal dichalcogenides, electronic crystal, excitonic crystal, Lindemann criterion

中图分类号:  (Electron solids)

  • 73.20.Qt
73.21.Cd (Superlattices) 73.21.Ac (Multilayers) 73.43.Cd (Theory and modeling)