Serbyn M N, Skvortsov M A, Varlamov A A, Galitski Victor
Landau Institute for Theoretical Physics, Chernogolovka, Moscow Region, 142432, Russia.
Phys Rev Lett. 2009 Feb 13;102(6):067001. doi: 10.1103/PhysRevLett.102.067001. Epub 2009 Feb 9.
A theory of the fluctuation-induced Nernst effect is developed for a two-dimensional superconductor in a perpendicular magnetic field. First, we derive a simple phenomenological formula for the Nernst coefficient, which naturally explains the giant Nernst signal due to fluctuating Cooper pairs. The latter signal is shown to be large even far from the transition and may exceed by orders of magnitude the Fermi liquid terms. We also present a complete microscopic calculation of the Nernst coefficient for arbitrary magnetic fields and temperatures, which is based on the Matsubara-Kubo formalism. It is shown that the magnitude and the behavior of the Nernst signal observed experimentally in disordered superconducting films can be well understood on the basis of superconducting fluctuation theory.
针对处于垂直磁场中的二维超导体，发展了一种涨落诱导能斯特效应理论。首先，我们推导了一个能斯特系数的简单唯象公式，它自然地解释了由库珀对涨落引起的巨大能斯特信号。结果表明，即使远离转变温度，后一种信号仍然很大，并且可能比费米液体项大几个数量级。我们还基于松原 - 久保形式给出了任意磁场和温度下能斯特系数的完整微观计算。结果表明，基于超导涨落理论可以很好地理解在无序超导薄膜中实验观测到的能斯特信号的大小和行为。
