Lifshitz时空s波超导模型的关联长度和穿透深度  

Coherence length and magnetic penetration depth of the s-wave holographic superconductor model in Lifshitz spacetime

作　　者：杨卓群[1] 吴亚波[1] 鲁军旺 张成园 张雪[1] 

机构地区：[1]辽宁师范大学物理与电子技术学院,大连116029 [2]黔南民族师范学院物理与电子科学系,都匀558000

出　　处：《物理学报》2016年第4期16-21,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11175077;11575075)资助的课题~~

摘　　要：在D=d+2维各向异性的Lifshitz黑洞时空背景中,在探子极限下,用解析方法研究了临界温度附近引力系统的微扰,计算出超导的关联长度ξ∝1/Tc(1-T/Tc)^(-1/2),这与平均场论的结果一致.进一步,考虑在该系统中加一个均匀外磁场,计算出穿透深度λ∝(Tc-T)^(-1/2),该结果与Ginzburg-Landau理论相符.The （anti-de Sitter/conformal field theory, AdS/CFT） duality provides us a powerful guidance to study the strong- coupled conformal field theory by using its dual weak-coupled gravity. One of the interesting applications of the duality is to study high temperature superconductors, which are supposed to be a strongly coupled system. According to Ginzburg- Landau theory, a superconductor can be characterized by only two parameters, coherence length ξ and the magnetic penetration length A; therefore, it is important to determine the two parameters. ＇In this paper in the D ---- d ＋2- dimensional Lifshitz black hole, we analytically study the static fluctuation of the scalar field with nonzero spatial momentum along one spatial coordinate of the boundary, and investigate the perturbation of the gravitational system near the critical temperature To. Working in the probe limit （the gauge field and scalar field do not backreact on the original metric）, we obtain the superconducting coherence length ξ via AdS/CFT correspondence, which isξ ∝1/Tc（1-T/Tc）^-1/2. Moreover, in the probe limit （the magnetic field does not backreact to the background spacetime）, we have calculated the diamagnetic current induced by a homogeneous external magnetic field perpendicular to the surface of the superconductor. Then, we obtain the magnetic penetration depth λ ∝（ （To - T）^-1/2 which agrees with the result in Ginzburg-Landau theory. And these results strongly support the idea that a superconductor can be described by a charged scalar field on the Lifshitz black hole via AdS/CFT duality.

关 键 词：全息超导 Lifshitz黑洞 关联长度 穿透深度 

分 类 号：O412.1[理学—理论物理] P145.8[理学—物理]