Pressure induced effects on the Fermi surface of superconducting 2H-NbSe2

Phys Rev Lett. 2005 Sep 9;95(11):117006. doi: 10.1103/PhysRevLett.95.117006. Epub 2005 Sep 9.

Abstract

The pressure dependence of the critical temperature T(c) and upper critical field H(c2)(T) has been measured up to 19 GPa in the layered superconducting material 2H-NbSe2. T(c)(P) has a maximum at 10.5 GPa, well above the pressure for the suppression of the charge density wave (CDW) order. Using an effective two-band model to fit H(c2)(T), we obtain the pressure dependence of the anisotropy in the electron-phonon coupling and Fermi velocities, which reveals the peculiar interplay between CDW order, Fermi surface complexity, and superconductivity in this system.