Unusual evolution of B_{c2} and T_c with inclined fields in restacked TaS_2 nanosheets

TL;DR

This study investigates the unusual enhancement of superconductivity in restacked TaS_2 nanosheets under inclined magnetic fields, revealing a significant increase in upper critical field and a dome-shaped T_c phase diagram due to microstructure and spin-orbit effects.

Contribution

It introduces an extended Ginzburg-Landau model to explain the enhanced superconductivity and anisotropic effects in restacked TaS_2 nanosheets with unique microstructure and spin-orbit coupling.

Findings

Observed up to 3.8 times increase in B_{c2} under inclined fields.

Discovered dome-shaped T_c dependence on in-plane magnetic field.

Proposed an extended GL model considering microstructure effects.

Abstract

Recently we reported an enhanced superconductivity in restacked monolayer TaS_2 nanosheets compared with the bulk TaS_2, pointing to the exotic physical properties of low dimensional systems. Here we tune the superconducting properties of this system with magnetic field along different directions, where a strong Pauli paramagnetic spin-splitting effect is found in this system. Importantly, an unusual enhancement as high as 3.8 times of the upper critical field B_{c2}, as compered with the Ginzburg-Landau (GL) model and Tinkham model, is observed under the inclined external magnetic field. Moreover, with the out-of-plane field fixed, we find that the superconducting transition temperature T_c can be enhanced by increasing the in-plane field and forms a dome-shaped phase diagram. An extended GL model considering the special microstructure with wrinkles was proposed to describe the results. The restacked crystal structure without inversion center along with the strong spin-orbit coupling may also play an important role for our observations.