Non-universal ordering of spin and charge in stripe phases

TL;DR

This paper investigates the complex interactions and phase transitions of topological defects in stripe phases, revealing non-universal critical behavior and conditions for simultaneous or separate loss of spin and charge order.

Contribution

It provides a detailed renormalization-group analysis of defect interactions in stripe phases, highlighting non-universal transitions and the possibility of spin-charge separation.

Findings

Phase diagram with multiple transition scenarios

Identification of non-universal critical exponents

Conditions for simultaneous or sequential loss of order

Abstract

We study the interplay of topological excitations in stripe phases: charge dislocations, charge loops, and spin vortices. In two dimensions these defects interact logarithmically on large distances. Using a renormalization-group analysis in the Coulomb gas representation of these defects, we calculate the phase diagram and the critical properties of the transitions. Depending on the interaction parameters, spin and charge order can disappear at a single transition or in a sequence of two transitions (spin-charge separation). These transitions are non-universal with continuously varying critical exponents. We also determine the nature of the points where three phases coexist.