Mechanisms of screening or enhancing the pseudogap throughout the two-band Bardeen-Cooper-Schrieffer to Bose-Einstein condensate crossover

Article

关键词: FESHBACH RESONANCE;    SUPERCONDUCTIVITY;    PHASE;    FLUCTUATIONS;    TEMPERATURE;    TRANSITION;    BEHAVIOR;    BCS;   

DOI  :  10.1103/PhysRevB.102.220504

来源: SCIE

【 摘 要 】

We demonstrate the rise and fall of multiple pseudogaps in the Bardeen-Cooper-Schrieffer to Bose-Einstein condensation crossover in two-band fermionic systems having different pairing strengths in the deep band and in the shallow band. The striking features of this phenomenon are an unusual many-body screening of the pseudogap state and the importance of pair-exchange couplings, which induces multiple pseudogap formation in the two bands. The multiband configuration suppresses pairing fluctuations and the pseudogap opening in the strongly interacting shallow band at small pair-exchange couplings by screening effects, with a possible connection to the pseudogap phenomenology in iron-based superconductors. On the other hand, the multiple pseudogap mechanism is accompanied by the emergence of binary preformed Cooper pairs originating from the interplay between intraband and pair-exchange couplings.

【 授权许可】

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