Anisotropic superconductivity in NbSe2 probed by magnetic penetration depth

Pascale Diener (1) , Pierre Rodiere (1) , John D Fletcher (2) , Anthony Carrington (2) , Jean-Pascal Brison (3, 1) , Ruslan Prozorov (4, 5) , T. Olheise (6) , Rw Giannetta (6)

1 CRTBT - Centre de Recherches sur les Très Basses Températures
2 University of Bristol [Bristol]
3 SPSMS - UMR 9001 - Service de Physique Statistique, Magnétisme et Supraconductivité
4 Ames Laboratory [Ames, USA]
5 Department of Physics and Astronomy [Ames, Iowa]
6 UIUC - University of Illinois at Urbana-Champaign [Urbana]

NbSe2 shows coexistence of a charge density wave (TCDW similar to 32 K) with a superconducting state below T = 7.2 K. Recent ARPES measurements revealed different values of the superconducting gap on the main sheets of the Fermi surface. These results suggest a multigap superconductivity such as in MgB2. The temperature dependence of the magnetic penetration depth (;.(T)) down to T,11 6 has been measured on high quality single crystals in the Meissner state. A strong increase of the in-plane penetration depth is observed, signaling the presence of low lying excitations. Given the relative contributions of each Fermi surface sheet, these measurements indicate that a reduced gap is not necessarily only found on the small Se sheet as suggested by the ARPES measurements. These results are discussed in a framework of multigap superconductivity.

Domaines: Supraconductivité [cond-mat.supr-con]

Pascale Diener, Pierre Rodiere, John D Fletcher, Anthony Carrington, Jean-Pascal Brison, et al.. Anisotropic superconductivity in NbSe2 probed by magnetic penetration depth. 8th International Conference on Materials and Mechanisms of Superconductivity and High Temperature Superconductors, Jul 2006, Dresden, Germany. pp.700, ⟨10.1016/j.physc.2007.03.145⟩. ⟨hal-00965453⟩