中国物理B ›› 2022, Vol. 31 ›› Issue (12): 126401-126401.doi: 10.1088/1674-1056/ac8ce1
Zhanglin Hou(侯章林)1,2,3,†,‡, Jieli Wang(王杰利)1,†, Ying Zeng(曾颖)4, Zhiyuan Zhao(赵志远)1,3, Xing Huang(黄兴)1,3, Kun Zhao(赵坤)5,6,§, and Fangfu Ye(叶方富)1,3,7,8,9,¶
Zhanglin Hou(侯章林)1,2,3,†,‡, ‡1,†, Jieli Wang(王杰利)4, Ying Zeng(曾颖)1,3, Zhiyuan Zhao(赵志远)1,3, Xing Huang(黄兴)5,6,§, Kun Zhao(赵坤)1,3,7,8,9,¶
摘要: Two-dimensional (2D) melting is a fundamental research topic in condensed matter physics, which can also provide guidance on fabricating new functional materials. Nevertheless, our understanding of 2D melting is still far from being complete due to existence of possible complicate transition mechanisms and absence of effective analysis methods. Here, using Monte Carlo simulations, we investigate 2D melting of 60° rhombs which melt from two different surface-fully-coverable crystals, a complex hexagonal crystal (cHX) whose primitive cell contains three rhombs, and a simple rhombic crystal (RB) whose primitive cell contains one rhomb. The melting of both crystals shows a sequence of solid, hexatic in molecular orientation (Hmo), and isotropic phases which obey the Berezinskii-Kosterlitz-Thouless-Halperin-Nelson-Young (BKTHNY) theory. However, local polymorphic configuration (LPC) based analysis reveals different melting mechanisms: the cHX-Hmo transition is driven by the proliferation of point-like defects during which defect-associated LPCs are generated sequentially, whereas the RB-Hmo transition is driven by line defects where defect-associated LPCs are generated simultaneously. These differences result in the observed different solid-Hmo transition points which are φA=0.812 for the cHX-Hmo and φA=0.828 for the RB-Hmo. Our work will shed light on the initial-crystal-dependence of 2D melting behavior.
中图分类号: (General studies of phase transitions)