Bridging Quantum and Classical Descriptions of Spin Dynamics in a Dzyaloshinsky-Moriya Trimer

TL;DR

This paper explores the transition between quantum and classical descriptions of spin dynamics in a Dzyaloshinsky-Moriya trimer by solving a modified Schrödinger equation and analyzing the resulting dynamical behaviors.

Contribution

It introduces a unified Hamiltonian framework that interpolates between quantum and semiclassical regimes for spin dynamics, providing new insights into their boundary.

Findings

Dynamical behavior varies from quantum to semiclassical with different DM interaction levels.

A ground state diagram illustrates the evolution of spin motion character.

Theoretical analysis of chiral spin dynamics at the quantum-classical boundary.

Abstract

The spin dynamics of a trimer with Dzyaloshinsky-Moriya (DM) interaction are investigated within a unified Hamiltonian framework that connects quantum-mechanical and semiclassical descriptions. The interpolation between the two regimes is realised by solving the modified Gisin-Schr\"odinger equation, in which the relative weight of a quantum coherence and local mean-field contributions is continuously tuned. The resulting dynamical behaviour is analysed and summarised in a ground state diagram that illustrates how the character of the spin motion evolves from fully quantum to semiclassical as the DM interaction is treated at different levels of approximation. In the last part of the publication, the chiral spin dynamics proposed by Da-Wei Wang et al. is examined theoretically, taking into account its behaviour at the boundary between quantum and classical physics.