Fermi Surface Sheet-Dependent Superconductivity in 2H-NbSe2
T. Yokoya,1*
T. Kiss,1
A. Chainani,12
S. Shin,13
M. Nohara,4
H. Takagi4
High-resolution angle-resolved photoemission spectroscopy was used
to study the superconducting energy gap and changes in the spectral
function across the superconducting transition in the
quasi-two-dimensional superconductor 2H-NbSe2.
The momentum dependence of the superconducting gap was determined on
different Fermi surface sheets. The results indicate Fermi surface
sheet-dependent superconductivity in this low-transition temperature
multiband system and provide a description consistent with
thermodynamic measurements and the anomalous de Haas-van Alphen
oscillations observed in the superconducting phase. The present data
suggest the importance of Fermi surface sheet-dependent
superconductivity in explaining exotic superconductivity in other
multiband systems with complex Fermi surface topology, such as the
borides and f-electron superconductors.
1 Institute for Solid State Physics, University
of Tokyo, Kashiwa, Chiba 277-8581, Japan.
2 Institute for Plasma Research, Bhat,
Gandhinagar-382 428, India.
3 The Institute of
Physical and Chemical Research (RIKEN), Sayo-gun, Hyogo 679-5143, Japan.
4 Department of Advanced Materials Science,
University of Tokyo, Tokyo 113-0033, Japan.
*
To whom correspondence should be addressed. E-mail:
yokoya{at}issp.u-tokyo.ac.jp
