Realistic magnetic thermodynamics by local quantization of a semiclassical Heisenberg model
Abstract
Classical Monte Carlo simulation of the Heisenberg model poorly describes many thermodynamic phenomena due to its neglect of the quantum nature of spins. Alternatively, we discuss how to semiclassically approach the quantum problem and demonstrate a simple method for introducing a locally approximate form of spin quantization. While the procedure underestimates magnetic short-range order, our results suggest a simple correction for recovering realistic spin–spin correlations above the critical temperature. Moreover, ensemble fluctuations are found to provide reasonably accurate thermodynamics, largely reproducing quantum mechanically calculated heat capacities and experimental magnetometry for ferromagnetic Fe and antiferromagnetic RbMnF3. Extensions of the method are proposed to address remaining inaccuracies.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 30, 2022
- Source ID
- 10.1038/s41524-022-00875-8
Entities
People
- Flynn Walsh
- Lin-Wang Wang
- Mark Asta
Organizations
- Army Research Office
- Office of Basic Energy Sciences