When superconductivity crosses over: From BCS to BEC
Qijin Chen, Zhiqiang Wang, Rufus Boyack, Shuolong Yang, K. Levin
Abstract
The theory of unconventional superconductors continues to provide profound puzzles. The crossover between the weakly coupled Bardeen-Cooper-Schrieffer (BCS) state and the strong-pairing Bose-Einstein condensate (BEC) provides a useful perspective on how to address these questions. This paper describes a self-consistent framework for thinking about the crossover regime in between these two limits. The review discusses to what extent this BCS-BEC theory applies to a range of classes of superconducting materials including the cuprates, iron pnictides, twisted bilayer graphene, and interfacial superconductivity among others.
Topics & Concepts
PhysicsSuperconductivityTheoretical physicsParticle physicsCondensed matter physicsPhysics of Superconductivity and MagnetismIron-based superconductors researchSuperconducting Materials and Applications