发表机构
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences; University of Chinese Academy of Sciences; Songshan Lake Materials Laboratory（中国科学院物理研究所; 中国科学院大学; 松山湖材料实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过蒙特卡洛模拟和Ginzburg–Landau理论，揭示kagome晶格上三-Q环路电流序的两阶段熔化机制，提出残留手性序的定量畴壁判据，为时间反演对称性破缺提供热力学解释。
AI 中文摘要
多组分序可以分阶段熔化，在其主要组分变为短程有序后留下复合序。我们研究了kagome晶格上相称的三-Q环路电流序的这种可能性。大规模团簇和并行回火蒙特卡洛模拟揭示了有效固定振幅符号模型中的直接和两阶段熔化区域。在后一种区域中，平移扇区畴壁在改变手性的畴壁之前增殖，恢复了晶格平移对称性，同时保持了长程时间反演奇序。在该中间相中，主要的M点相关性是短程的。当最低能量的改变手性畴壁仅比同手性平移壁昂贵约12%–13%时，两阶段区域开始。稳定振幅分辨的Ginzburg–Landau理论的有限尺寸标度表明，该相在振幅弛豫下存活。我们的结果建立了残留环路电流序的定量畴壁判据，以及一种在没有长程环路电流Bragg序的情况下实现时间反演对称性破缺的涨落途径。这种分离为最近在kagome金属中常规电荷密度波有序临界温度以上报告的时间反演奇响应提供了可能的热力学框架。
英文摘要
Multicomponent order can melt in stages, leaving a composite order after its primary constituents become short ranged. We study this possibility for commensurate three-$Q$ loop-current order on the kagome lattice. Large-scale cluster and parallel-tempering Monte Carlo simulations reveal direct and two-stage melting regimes in an effective fixed-amplitude sign model. In the latter regime, translation-sector domain walls proliferate before chirality-changing walls, restoring lattice translational symmetry while preserving long-range time-reversal-odd order. The primary $M$-point correlations are short ranged in this intermediate phase. The two-stage regime begins when the lowest-energy chirality-changing wall is only about $12$--$13\%$ more costly than a same-chirality translation wall. Finite-size scaling of a stable amplitude-resolved Ginzburg--Landau theory shows that the phase survives amplitude relaxation. Our results establish a quantitative domain-wall criterion for vestigial loop-current order and a fluctuation route to time-reversal symmetry breaking without long-range loop-current Bragg order. This separation provides a possible thermodynamic framework for time-reversal-odd responses recently reported above the critical temperature for conventional charge-density-wave ordering in kagome metals.
Comments11 pages, 5 figures
