Spin dynamics of quantum and classical Heisenberg dimers

TL;DR

This paper provides analytical solutions for the time-dependent autocorrelation functions of classical and quantum Heisenberg dimers with arbitrary spin, highlighting their similarities at large spins or high temperatures and the fundamental difference in periodicity.

Contribution

It offers a comparative analysis of classical and quantum spin dimers with analytical solutions for autocorrelation functions across arbitrary spins.

Findings

Quantum autocorrelation functions are periodic in time.

Classical and quantum dimers become similar at large spins or high temperatures.

Quantum autocorrelation exhibits periodicity, unlike the classical case.

Abstract

Analytical solutions for the time-dependent autocorrelation function of the classical and quantum mechanical spin dimer with arbitrary spin are presented and compared. For large spin quantum numbers or high temperature the classical and the quantum dimer become more and more similar, yet with the major difference that the quantum autocorrelation function is periodic in time whereas the classical is not.