Non-Fermi liquid scattering against an emergent Bose liquid: manifestations in the kink and other exotic quasiparticle behaviors in the normal-state cuprate superconductors

TL;DR

This paper explains the non-Fermi liquid behaviors in cuprate superconductors as arising from scattering against an emergent Bose liquid, linking experimental phenomena like the kink and pseudogap to this mechanism.

Contribution

It introduces a novel theoretical framework where non-Fermi liquid behaviors emerge naturally from fermion scattering off an emergent Bose liquid in cuprates.

Findings

Finite zero-energy scattering rate at low temperature grows linearly with temperature

Reproduction of the 'kink' feature in quasiparticle dispersion

Connection between normal state behavior and superconducting state phenomena

Abstract

The normal state of cuprate superconductors exhibits many exotic behaviors qualitatively different from the Fermi liquid, the foundation of condensed matter physics. Here we demonstrate that non-Fermi liquid behaviors emerge naturally from scattering against an emergent Bose liquid. Particularly, we find a finite zero-energy scattering rate at low-temperature limit that grows linearly with respect to temperature, against clean fermions' generic non-dissipative characteristics. Surprisingly, three other seemingly unrelated experimental observations are also produced, including the well-studied "kink" in the quasi-particle dispersion, as well as the puzzling correspondences between the normal and superconducting state. Our findings provide a general route for fermionic systems to generate non-Fermi liquid behavior, and suggest strongly that by room temperature the doped holes in the cuprates have already formed an emergent Bose liquid of tightly bound pairs, whose low-temperature condensation gives unconventional superconductivity.