掺杂棋盘晶格中的d波超导配对对称性  

d-wave superconducting pairing symmetry in doped checkerboard lattice

作　　者：潘月 马润宇 马天星[1] PAN Yue;MA Runyu;MA Tianxing(Department of Physics,Beijing Normal University,100875,Beijing,China)

机构地区：[1]北京师范大学物理学系,北京100875

出　　处：《北京师范大学学报（自然科学版）》2023年第6期920-925,共6页Journal of Beijing Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11974049)。

摘　　要：如何理解棋盘晶格中的强关联电子现象是一个值得深入研究的问题.在阻挫系统中,量子蒙特卡罗模拟通常会遇到符号问题.我们采用约束路径量子蒙特卡罗方法,有效地避开符号问题,研究了定义在掺杂棋盘晶格Hubbard模型中的超导配对关联.我们发现:d波对称性的超导配对关联函数优于其他对称性;d波配对关联函数随着次近邻跃迁强度t′的减小而增大,随着库仑相互作用的增加而增大.研究结果为进一步理解超导体中的关联效应及其超导配对机制提供了有价值的参考,也为理解阻挫和超导的关系提供了思路.To understand strong correlated electron states in a checkerboard lattice is an important problem.In frustrated systems,quantum Monte Carlo simulation often suffers the sign problem.We use constrained path quantum Monte Carlo(CPQMC)method to effectively avoid the sign problem,and study superconducting pairing correlation in doped Hubbard model on a checkerboard lattice.Superconducting pairing correlation function with d-wave symmetry is found to dominate over other symmetries.The d-wave pairing correlation function increases with next-nearest neighbor hopping strength’decreases,and increases when the Coulomb interaction increases.These data provide some valid points for further theoretical research on correlation effect and superconductivity in superconductors,and also provide ideas for understanding relationship between frustration and superconductivity.

关 键 词：棋盘晶格 超导电性 量子蒙特卡罗方法 配对对称性 

分 类 号：O469[理学—凝聚态物理]