Zeeman-Induced Gapless Superconductivity with Partial Fermi Surface

TL;DR

This paper demonstrates that an in-plane magnetic field can induce a gapless superconducting phase with a reconstructed Fermi surface in spin-orbit-coupled 2D systems, revealing novel quasiparticle states and potential material platforms.

Contribution

It introduces the concept of Zeeman-induced gapless superconductivity with partial Fermi surfaces in 2D spin-orbit-coupled systems under magnetic fields.

Findings

Partial Fermi surfaces are formed at zero energy.

Charge distribution and spin texture are characterized.

Material platforms for realization are proposed.

Abstract

We show that an in-plane magnetic field can drive two-dimensional spin-orbit-coupled systems under superconducting proximity effect into a gapless phase where parts of the normal state Fermi surface are gapped, and the ungapped parts are reconstructed into a small Fermi surface of Bogoliubov quasiparticles at zero energy. Charge distribution, spin texture, and density of states of such "partial Fermi surface" are discussed. Material platforms for its physical realization are proposed.