Spontaneous orientation of a quantum lattice string

TL;DR

This paper investigates the ground state properties of a quantum lattice string model for cuprate stripes, revealing spontaneous symmetry breaking where the string becomes directionally oriented at zero temperature.

Contribution

It introduces an order parameter for string directedness and demonstrates spontaneous orientation in the ground state using exact diagonalization and quantum Monte Carlo methods.

Findings

Spontaneous symmetry breaking occurs at zero temperature.

The string becomes directed along one spatial axis.

The order parameter saturates at zero temperature.

Abstract

Using exact diagonalization and quantum Monte-Carlo techniques we study a quantum lattice string model introduced as a model for a single cuprate struipe. We focus on the ground state properties of the string. Our results shows that, in the physically relevant region of the parameter space, a zero temperature spontaneous symmetry breaking occures. The string spontaneously orients itself along one direction in space and become directed. We introduce an order parameter for the directedness and show that at zero temperature this order parameter reaches its saturation value.