Quantum analog of Landau-Lifshitz-Gilbert dynamics

• DOI: 10.48550/arxiv.2403.09255
• Publication Date: 2024-03-14
• Authors: Yuefei Liu; I. P. Miranda; Johnson Lee; Anders Bergman; Anna Delin; Danny Thonig; Manuel Pereiro; Olle Eriksson; Vahid Azimi Mousolou; Erik Sjöqvist
• Keywords: Landau quantization; Landau–Lifshitz–Gilbert equation; Dynamics

The Landau-Lifshitz-Gilbert (LLG) and Landau-Lifshitz (LL) equations play an essential role for describing the dynamics of magnetization in solids. While a quantum analog LL has been proposed [Phys. Rev. Lett. 110, 147201 (2013)], corresponding version LLG remains unknown. Here, we propose such equation that inherently conserves purity state. We examine dimer consisting two interacting spin-1/2 particles. Our analysis reveals that, case ferromagnetic coupling, evolution initially uncorrelated spins mirrors classical dynamics. However, antiferromagnetic scenario, observe pronounced deviations from behavior, underscoring unique becoming spinless state, which is non-locally correlated. Moreover, when considering are correlated, our study uncovers unusual form transient correlation dynamics, differ significantly what typically seen open systems.