Spin-Orbit-Parity-Coupled Superconductivity in Topological Monolayer WTe_{2}

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Monolayer 1T^{'}-WTe_{2} exhibits gate-induced superconductivity and is a topological insulator.
• Observed upper critical field (B_{c2}) exceeds the Pauli paramagnetic limit (B_{p}), unexplained by conventional spin-orbit coupling.
• Inversion symmetry in centrosymmetric 1T^{'}-WTe_{2} complicates standard explanations for enhanced critical fields.

Purpose of the Study:

• To elucidate the distinctive superconducting properties of centrosymmetric 1T^{'}-WTe_{2}.
• To explain the enhanced upper critical field beyond the Pauli limit.
• To investigate the role of spin-orbit-parity coupling (SOPC) in superconductivity.

Main Methods:

• Theoretical investigation of superconducting properties in centrosymmetric 1T^{'}-WTe_{2}.
• Analysis of the interplay between spin, momentum, and band parity degrees of freedom.
• Exploration of the impact of spin-orbit-parity coupling on superconducting transitions and critical fields.

Main Results:

• A first-order superconductor-metal transition at B_{c2}, significantly above B_{p}, is predicted.
• Anisotropic spin susceptibility and potential for anisotropic B_{c2} due to SOPC.
• Strong gate dependence of B_{c2} linked to SOPC's significance near topological band crossings.

Conclusions:

• Spin-orbit-parity coupling is identified as the mechanism behind the enhanced B_{c2} in 1T^{'}-WTe_{2}.
• SOPC influences the superconducting transition order and critical field anisotropy.
• The theoretical framework is applicable to other centrosymmetric materials with topological band inversions.