NbSe₂ 涡旋态中的热传导：多带超导性的证据

Heat conduction in the vortex state of NbSe2: evidence for multiband superconductivity.

作者信息

Boaknin Etienne, Tanatar M A, Paglione Johnpierre, Hawthorn D, Ronning F, Hill R W, Sutherland M, Taillefer Louis, Sonier Jeff, Hayden S M, Brill J W

机构信息

Department of Physics, University of Toronto, Toronto, Ontario, Canada.

出版信息

Phys Rev Lett. 2003 Mar 21;90(11):117003. doi: 10.1103/PhysRevLett.90.117003. Epub 2003 Mar 18.

DOI:10.1103/PhysRevLett.90.117003

PMID:12688957

Abstract

The thermal conductivity kappa of the layered s-wave superconductor NbSe2 was measured down to T(c)/100 throughout the vortex state. With increasing field, we identify two regimes: one with localized states at fields very near H(c1) and one with highly delocalized quasiparticle excitations at higher fields. The two associated length scales are naturally explained as multiband superconductivity, with distinct small and large superconducting gaps on different sheets of the Fermi surface. This behavior is compared to that of the multiband superconductor MgB2 and the conventional superconductor V3Si.

摘要

在整个涡旋态下，对层状s波超导体NbSe₂的热导率κ进行了测量，直至温度低至T(c)/100。随着磁场增加，我们确定了两种状态：一种是在非常接近H(c1)的磁场下具有局域态，另一种是在较高磁场下具有高度离域的准粒子激发。这两个相关的长度尺度自然地被解释为多带超导性，在费米面的不同片上具有不同的小和大超导能隙。将这种行为与多带超导体MgB₂和传统超导体V3Si的行为进行了比较。