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Coherent Superconductivity with a Large Gap Ratio from Incoherent Metals

Cornell Affiliated Author(s)

Author

A.A. Patel
M.J. Lawler
Eun-Ah Kim

Abstract

A mysterious incoherent metallic (IM) normal state with T-linear resistivity is ubiquitous among strongly correlated superconductors. Recent progress with microscopic models exhibiting IM transport has presented the opportunity for us to study new models that exhibit direct transitions into a superconducting state out of IM states within the framework of connected Sachdev-Ye-Kitaev "quantum dots." Here, local Sachdev-Ye-Kitaev interactions within a dot produce IM transport in the normal state, while local attractive interactions drive superconductivity. Through explicit calculations, we find two features of superconductivity arising from an IM normal state. First, despite the absence of quasiparticles in the normal state, the superconducting state still exhibits coherent superfluid transport. Second, the nonquasiparticle nature of the IM Green's functions produces a large enhancement in the ratio of the zero-temperature superconducting gap Δ and transition temperature TSC, 2Δ/TSC, with respect to its BCS value of 3.53. © 2018 American Physical Society.

Date Published

Journal

Physical Review Letters

Volume

121

Issue

18

URL

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056081799&doi=10.1103%2fPhysRevLett.121.187001&partnerID=40&md5=be4ab90a83050d996239c8e9ee8bc22c

DOI

10.1103/PhysRevLett.121.187001

Group (Lab)

Michael Lawler Group

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