Phase coherence of charge-6e superconductors with a frustrated Kagome XY antiferromagnet  

作　　者：Feng-Feng Song Guang-Ming Zhang 宋峰峰;张广铭(Institute for Solid State Physics,The University of Tokyo,Kashiwa,Chiba 277-8581,Japan;State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing 100084,China;School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China;Frontier Science Center for Quantum Information,Beijing 100084,China)

机构地区：[1]Institute for Solid State Physics,The University of Tokyo,Kashiwa,Chiba 277-8581,Japan [2]State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing 100084,China [3]School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China [4]Frontier Science Center for Quantum Information,Beijing 100084,China

出　　处：《Chinese Physics Letters》2025年第3期180-185,共6页中国物理快报(英文版)

基　　金：supported by the National Key Research and Development Program of China(Grant No.2023YFA1406400)。

摘　　要：Recent experimental evidence of the charge-6e condensed phase in Kagome superconductors has generated significant interest.This study investigates the unconventional superconductivity in the Kagome superconductor CsV_(3)Sb_(5),focusing on the emergence of charge-6e superconductivity(SC)at temperatures higher than the conventional charge-2e SC state.By modeling the phase coherence of the SC order parameter using a frustrated antiferromagnetic XY model on an emergent Kagome lattice,the condensation of fractional vortices with 1/3 vorticity stabilizes the phase coherence in exp(i3θ),resulting in a charge-6e SC state.Using a tensor network approach tailored for frustrated spin systems,a Berezinskii-Kosterlitz-Thouless transition is identified at T_(c)/J≃0.075,where the unbinding of 1/3 fractional vortex-antivortex pairs transforms the system from the charge-6e SC phase to the normal phase.Below T_(c),the 1/3 fractional vortex correlations exhibit a power-law decay,whereas the integer vortex correlations decay exponentially,reflecting the dominance of charge-6e SC in the absence of charge-2e SC.The results provide a theoretical understanding of charge-6e SC in two-dimensional Kagome superconductors,emphasizing the interaction between fractional vortices,frustration,and topology in stabilizing the exotic SC phase.

关 键 词：state. CHARGE FRACTIONAL 

分 类 号：O17[理学—数学]