Strange Metals from Quantum Geometric Fluctuations of Interfaces

TL;DR

This paper introduces a novel framework for understanding strange metallic behavior near the Mott transition by considering quantum geometric fluctuations of interfaces, leading to non-Fermi liquid states and pairing mechanisms.

Contribution

It proposes a real space model incorporating interface fluctuations as bosonic strings, revealing their role in non-Fermi liquid behavior and electron pairing near the Mott transition.

Findings

Critical geometric fluctuations induce non-Fermi liquid behavior.

Fermion Green's function poles become zeros, indicating absence of quasiparticles.

Quantum geometric fluctuations mediate Cooper pairing.

Abstract

Our current understanding of strongly correlated electron systems is based on a homogeneous framework. Here we take a step going beyond this paradigm by incorporating inhomogeneity from the beginning. Specifying to systems near the Mott metal-insulator transition, we propose a real space picture of itinerant electrons functioning in the fluctuating geometries bounded by interfaces between metallic and insulating regions. In 2+1-dimensions, the interfaces are closed bosonic strings, and we have a system of strings coupled to itinerant electrons. When the interface tension vanishes, the geometric fluctuations become critical, which gives rise to non-Fermi liquid behavior for the itinerant electrons. In particular, the poles of the fermion Green's function can be converted to zeros, indicating the absence of propagating quasiparticles. Furthermore, the quantum geometric fluctuations mediate Cooper pairing among the itinerant electrons, indicating the intrinsic instability of electronic systems near the Mott transition.