title: Superconducting density of states and vortex cores of 2H-NbS2.
abstract: Scanning tunneling microscopy and spectroscopy measurements in the superconducting dichalcogenide 2H-NbS2 show a peculiar superconducting density of states with two well-defined features at 0.97 and 0.53 meV, located, respectively, above and below the value for the superconducting gap expected from the single band s-wave BCS model (Delta=1.76k_(B)T_(c)=0.9 meV). Both features have a continuous temperature evolution and disappear at T_(c)=5.7 K. Moreover, we observe the hexagonal vortex lattice with radially symmetric vortices and a well-developed localized state at the vortex cores. The sixfold star shape characteristic of the vortex lattice of the compound 2H-NbSe2 is, together with the charge density wave order, absent in 2H-NbS2.
authors.affiliation: Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Facultad de Ciencias Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Guillamón
authors.forename: H
authors.initials: H
authors.lastname: Suderow
authors.forename: S
authors.initials: S
authors.lastname: Vieira
authors.forename: L
authors.initials: L
authors.lastname: Cario
authors.forename: P
authors.initials: P
authors.lastname: Diener
authors.forename: P
authors.initials: P
authors.lastname: Rodière