长程库仑势对高温超导涡旋电荷的影响

Long-range Coulomb Interaction Effect on a Charged Vortex in High-temperature Superconductors

基于Bogoliubov-de Gennes理论,研究了高温超导涡旋电荷符号受长程库仑势的影响.数值结果表明:对稍过掺杂样品,当反铁磁序变强,涡旋电荷的符号发生改变;而对欠掺杂状态,引入长程库仑势并使其强度增强,反铁磁序会受到压制从而强度变弱.在反铁磁序背景下,长程库仑势的值达到一定范围时也能够观察到正涡旋电荷,这对核磁共振实验结果提供了很好的解释.

Based on the framework of the Bogoliubov-de Gennes theory,the influence of the long-range Coulomb interaction to the high-temperature superconductor(HTSCs)charged vortex were investigated.The numerical results indicated that for slightly overdoped HTSCs,with the enhancement of the AFM order,a sign change between positive to negative occurred,whereas,for underdoped HTSCs,because of the increasing of the long-range Coulomb interaction,the AFM was reduced. When the long-range Coulomb interaction had been introduced and enhanced,the positive vortex charge for underdoped samples which had large AFM order was observed as well,which provided valid explanation for the recent experiments.