Enhancement of superconductivity under pressure and the magnetic phase diagram of tantalum disulfide single crystals.

ABSTRACT: In low-dimensional electron systems, charge density waves (CDW) and superconductivity are two of the most fundamental collective quantum phenomena. For all known quasi-two-dimensional superconductors, the origin and exact boundary of the electronic orderings and superconductivity are still attractive problems. Through transport and thermodynamic measurements, we report on the field-temperature phase diagram in 2H-TaS2 single crystals. We show that the superconducting transition temperature (Tc) increases by one order of magnitude from temperatures at 0.98?K up to 9.15?K at 8.7?GPa when the Tc becomes very sharp. Additionally, the effects of 8.7?GPa illustrate a suppression of the CDW ground state, with critically small Fermi surfaces. Below the Tc the lattice of magnetic flux lines melts from a solid-like state to a broad vortex liquid phase region. Our measurements indicate an unconventional s-wave-like picture with two energy gaps evidencing its multi-band nature.

SUBMITTER: Abdel-Hafiez M 

PROVIDER: S-EPMC4989151 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature