Quantizing Charged Magnetic Domain Walls: Strings on a Lattice

TL;DR

This paper models the quantum behavior of charged magnetic domain walls in high-temperature superconductors using lattice string models, revealing complex phase diagrams with various rough and ordered phases.

Contribution

It introduces minimal lattice string models for quantizing charged domain walls, connecting them to well-studied spin chains and surface models.

Findings

Rich phase diagram with multiple rough phases

Existence of gapped ordered phases

Mapping to classical and quantum models

Abstract

The discovery by Tranquada et al. of an ordered phase of charged domain walls in the high-Tc cuprates leads us to consider the possible existence of a quantum domain-wall liquid. We propose minimal models for the quantization, by meandering fluctuations, of isolated charged domain walls. These correspond to lattice string models. The simplest model of this kind, a directed lattice string, can be mapped onto a quantum spin chain or on a classical two-dimensional solid-on-solid surface model. The model exhibits a rich phase diagram, containing several rough phases with low-lying excitations as well as ordered phases which are gapped.