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arXiv · 1908.02757

Intrinsic superconducting instabilities of a solvable model for an incoherent metal

Debanjan Chowdhury·Erez Berg
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Abstract

We construct a family of translationally invariant lattice models with a large number ($N$) of orbitals at every site coupled together via single electron tunneling. By tuning the relative strength of the electronic bandwidth and on-site interactions, that have a modified Sachdev-Ye-Kitaev (SYK) form, we demonstrate a number of unusual features at strong coupling and in the large$-N$ limit. We find examples of (i) an intrinsic non-BCS superconducting instability arising out of an incoherent non-Fermi liquid metal, and, (ii) an instability of an incipient heavy Fermi liquid metal to superconductivity with transition temperatures comparable to its renormalized bandwidth. At strong-coupling, these solvable models display pairing instabilities that are not driven by any special "nesting" properties associated with an underlying Fermi surface.

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Debanjan Chowdhury, Erez Berg. 2019-08-07. Intrinsic superconducting instabilities of a solvable model for an incoherent metal. https://doi.org/10.1103/physrevresearch.2.013301

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