A Toy Model of Interlayer Pair Hopping

TL;DR

This paper extends a correlated electron model to coupled layers, showing non-Fermi liquid behavior suppresses electron quasiparticles but allows singlet pair tunneling, suggesting a route to superconductivity.

Contribution

It introduces a layered extension of Baskaran's model, highlighting how pair tunneling can lead to superconducting states despite electron confinement.

Findings

Non-Fermi liquid ground state causes electron quasiparticle suppression.

Singlet pair motion remains unaffected by confinement.

Pair tunneling can induce superconductivity.

Abstract

We extend the correlated electron model of Baskaran [Mod. Phys. Lett. {\bf B5}, 643(1991)] to the case of coupled layers. We show that the nature of the non-Fermi liquid ground state leads to the absence of electron-like quasiparticles at the Fermi surface, thereby suppressing coherent transport of electrons between the coupled layers (``confinement''). On the other hand, motion of singlet pairs between the layers is not blocked. We also discuss how pair tunneling can be used to construct a superconducting ground state.