Geometrically-Frustrated Pseudogap Phase of Coulomb Liquids

TL;DR

This paper investigates how long-range Coulomb interactions with varying decay exponents influence charge ordering and frustration, revealing a broad pseudogap phase with unique properties in Coulomb liquids.

Contribution

It demonstrates that decreasing the interaction exponent suppresses charge order and promotes a pseudogap phase, highlighting the role of geometric frustration in Coulomb systems.

Findings

Charge ordering temperature $T_c$ decreases with lower $eta$

A broad pseudogap phase exists above $T_c$

Critical behavior near $T_c$ remains unchanged from short-range models

Abstract

We study a class of models with long-range repulsive interactions of the generalized Coulomb form $V(r)\sim 1/r^{\alpha}$. We show that decreasing the interaction exponent in the regime $\alpha < d$ dramatically depresses the charge ordering temperature $T_c$ in any dimension $d\ge 2$, reflecting the strong geometric frustration produced by long-range interactions. A nearly frozen Coulomb liquid then survives in a broad pseudogap phase found at $T > T_c$, which is characterized by an unusual temperature dependence of all quantities. In contrast, the leading critical behavior very close to the charge-ordering temperature remains identical as in models with short-range interactions.