High temperature dynamics in quantum compass models

TL;DR

This paper investigates the high temperature spin dynamics of quantum compass models using a moment expansion approach, linking the problem to lattice path enumeration and providing insights relevant to NMR experiments.

Contribution

It introduces a novel combinatorial method to analyze high temperature spin dynamics in compass models, connecting statistical mechanics with lattice path enumeration.

Findings

Derived time-dependent spin correlation functions for Kitaev and 2D compass models

Mapped spin dynamics to a lattice path enumeration problem

Provides a visualization framework for high temperature spin behavior

Abstract

We analyze the high temperature spin dynamics of compass models using a moment expansion. We point out that the evaluation of moments maps to the enumeration of paths in a branching process on the lattice. This mapping to a statistical mechanics combinatorics problem provides an elegant visualization of the analysis. We present results for the time dependent spin correlation function (which is of relevance to NMR experiments) for two compass models: the Kitaev honeycomb model and two-dimensional compass model.