Cooper Molecules: Second Pairing of Cooper Pairs in Gapless Superconductor CeCoIn5

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2019,（10）
• 页码范围: 67-71
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/0256-307X/36/10/107401

摘要

We establish a quantum field theory of phase transitions in gapless superconductor CeCoIn5.It is found that uniform Cooper pair gases with pure gradient interactions with negative coefficient can undergo a Bardeen Cooper-Schrieffer (BCS) condensation below a critical temperature.In the BCS condensation state,bare Cooper pairs with opposite wave vectors are bound into Cooper molecules,and uncoupled bare Cooper pairs are trans-formed into a new kind of quasiparticle,i.e.,the dressed particles.The Cooper molecule system is a condensate or a superfluid,and the dressed particle system is a normal fluid.The critical temperature is derived analytically.The critical temperature of the superconductor CeCoIn5 is obtained to be Tc =2.289 K,which approaches the experimental data.The transition from the BCS condensation state to the normal state is a first-order phase transition.