On the Spin Gap Phase of Strongly-Correlated Electrons

TL;DR

This paper investigates the potential for a spin-gap phase in low-doping strongly-correlated 2D electrons, analyzing the effects of gauge field fluctuations and disorder on its stability.

Contribution

It extends previous work by showing the spin-gap phase is destroyed by gauge fluctuations even in the presence of disorder or a gapless spinon condensate.

Findings

Gauge fluctuations eliminate the spin-gap phase in the studied regimes.

Disorder does not stabilize the spin-gap phase against gauge fluctuations.

The results apply to both gapped and gapless spinon states.

Abstract

We discuss the possible existence of a spin-gap phase in the low-doping regime of strongly-correlated two-dimensional electrons within the gauge field description of the t-J model. The spin-gap phase was recently shown by Ubbens and Lee to be destroyed by gauge field quantum fluctuations for a single-layer 2D system in the absence of disorder and for a full gap. We show that the same conclusion applies both in the dirty limit and for the case of a gapless spinon condensate.