2011/10/29 by I. Fridman, Fridman, I., C. Kloc +4
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1110.6490
5 pages, 4 figures
arxiv created 2011/10/29 · openalex publication_date 2011/10/29 · arxiv updated 2011/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Scanning tunneling spectroscopy was performed on single crystals of superconducting 2H-NbSe2, at 300 mK and in a magnetic field, up to 5 T, applied parallel to the ab-plane. This novel field geometry allows the quasiparticle density-of-states spectrum to be measured under finite superfluid momentum, while avoiding contributions from the vortex-core bound states. At zero field, we observed a fully-gapped conductance spectrum with both gap-edge peaks and sub-gap kinks. These spectral features show a systematic evolution with the applied field: the kinks close in while the peaks move apart in low fields, and the zero-bias conductance has a two-sloped behavior over the entire field range, though dipping anomalously at 0.7 T. Our data was analyzed with recent theoretical models for quasiparticle tunneling into a current-carrying superconductor, and yielded distinct evidence for multiple superconducting gaps coming from various Fermi-surface sheets of different topologies, as well as possible implications on the origin of the coexisting charge-density-wave order.