Spin-triplet superconductivity from excitonic effect in doped insulators
Valentin Crépel, Liang Fu
Abstract
Significance We present a mechanism for unconventional superconductivity in doped band insulators, where short-ranged pairing interaction arises from Coulomb repulsion due to virtual interband or excitonic processes. Remarkably, electron pairing is found upon infinitesimal doping, giving rise to Bose–Einstein condensate (BEC)–Bardeen–Cooper–Schrieffer (BCS) crossover at low density. Our theory explains puzzling behaviors of superconductivity and predicts spin-triplet pairing in electron-doped ZrNCl and WTe 2 .
Topics & Concepts
Condensed matter physicsSuperconductivityDopingSpin (aerodynamics)PhysicsMaterials scienceThermodynamicsAdvanced Condensed Matter PhysicsPhysics of Superconductivity and MagnetismTopological Materials and Phenomena