Gap Anisotropy in Layered Superconductors Due to Rashba and Dresselhaus Spin-Orbit Interactions

Abstract

The theory of layered superconductors is extended in the presence of Rashba and Dresselhaus spin-orbit interactions (SOIs). Using the intralayer BCS-like pairing interaction and employing the Gor'kov formalism, we obtain analytical expressions for the temperature Green's functions and determine the gap function $\Delta$ which becomes complex in the presence of SOIs. In the absence of SOIs, $\Delta$ is isotropic at both zero and finite temperatures, but it becomes anisotropic even in the presence of a single SOI. This anisotropy is related to the extra $\cos k_z$ factors in which the $k_z$ momentum along the $z$ direction contributes to the magnitude of the gap function. It is also found that SOIs suppress $\Delta$ at both zero and finite temperatures, and for certain critical values of SOIs and beyond $\Delta$ vanishes. Analytical expressions for the critical values of SOIs at zero temperature are obtained. Additionally, how the BCS equation for layered superconductors changes in the presence of SOIs is determined.

13 pages, 5 figures

References in corpus (14)

• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• Scanning tunneling spectroscopy of high-temperature superconductors
• Non-Abelian Topological Order in S-Wave Superfluids of Ultracold Fermionic Atoms
• Measurement of Rashba and Dresselhaus spin-orbit magnetic fields
• Discovery of two-dimensional anisotropic superconductivity at KTaO${}_3$ (111) interfaces
• Two-dimensional superconductivity at the surfaces of KTaO3 gated with ionic liquid
• A comprehensive review on topological superconducting materials and interfaces
• Controllable Rashba spin-orbit interaction in artificially engineered superlattices involving the heavy-fermion superconductor CeCoIn5
• Band Structure and Spin-Orbital Texture of the (111)-KTaO3 Two-Dimensional Electron Gas
• Atomic-layer Rashba-type superconductor protected by dynamic spin-momentum locking
• Unconventional fully-gapped superconductivity in the heavy-fermion metal CeCu${}_2$Si${}_2$
• Strain engineering a persistent spin helix with infinite spin lifetime