Quantum critical behavior of electrons at the edge of charge order

TL;DR

This paper investigates quantum critical points driven by charge fluctuations in a 2D Hubbard model, revealing the vanishing of Fermi liquid coherence and potential quasiparticle destruction, with implications for layered organic materials.

Contribution

It introduces a finite-temperature analysis of charge-order quantum criticality in a 2D Hubbard model, highlighting the suppression of Fermi liquid behavior and mass enhancement effects.

Findings

Fermi liquid coherence scale T* vanishes at charge order transition

Strong effective mass enhancement near the QCP

Proposed experimental probes for layered organic materials

Abstract

We consider quantum critical points (QCP) in which quantum fluctuations associated with charge rather than magnetic order induce unconventional metallic properties. Based on finite-T calculations on a two-dimensional extended Hubbard model we show how the coherence scale T* characteristic of Fermi liquid behavior of the homogeneous metal vanishes at the onset of charge order. A strong effective mass enhancement reminiscent of heavy fermion behavior indicates the possible destruction of quasiparticles at the QCP. Experimental probes on quarter-filled layered organic materials are proposed for unveiling the behavior of electrons across the quantum critical region.