摘要
利用平均场t-t′-U-V-Vc模型,通过自洽求解Bogoliubov-de Gennes方程,研究了高温超导体中涡旋结构的相变.发现增大原位排斥势U,自旋密度波、电荷密度波以及d波序参量由棋盘结构转变为条纹结构.模型哈密顿量中引入合适强度的长程库仑势后,欠掺杂高温超导体样品中也可以出现二维或者棋盘结构,结果与文献报道的扫描隧道显微镜实验结果一致.
Vortex structures in high-temperature superconductors are studied by solving Bogoliubov-de Gennes equations based on a mean-field t-t'-U-V-Vo model. The results show that transition from checkerboard pattern to stripe structure for spin density wave, charge density wave, and d-wave orderings may occur by enhancing the strength of the on-site repulsion U. When a reasonable long-range Coulomb interaction is introduced into the model Hamiltonian, two-dimensional modulations or the checkerboard patterns may appear for the underdoped samples, which is consistent with the scanning-tunneling-microscopy experiments.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2009年第6期4189-4193,共5页
Acta Physica Sinica
基金
国家自然科学基金(批准号:60671042)
上海市学科建设项目(批准号:S30105)
上海大学研究生创新基金(批准号:shucx080121)资助的课题~~
关键词
高温超导
涡旋结构
长程库仑势
high-temperature superconductors, vortex structures, long-range Coulomb interaction