Monte Carlo Simulations of Langevin Spin dynamics in Magnetic Semiconductor Eu5Sn2As6
ORAL
Abstract
We discuss the results of a numerical study on the magnetic Zintl Eu5Sn2As6 [1], a semiconductor which exhibits colossal magnetoresistance, nontrivial magnetic order below 10K, and magnetic bound states. Classical Monte Carlo (MC) simulations using Sunny [2], a Julia package that implements efficient MC sampling with Langevin spin dynamics, reveal evolution of magnetic features in hysteresis and transitions between magnetic space groups with field and temperature. Spin configurations found using MC sampling offer a new tool for bounding the low-temperature exchange parameter, as well as a platform for the microscopic study of spin flops in this material. Conclusions on the magnetic structure and interactions between Europium moments from this method are discussed in the context of the well-studied Eu5In2Sb6 [3] and the broader Eu5M2X6 Zintl family, a class of materials predicted to be magnetic topological insulators [4].
*This research was supported by the Air Force Office of Scientific Research (AFOSR) Multidisciplinary University Research Initiative (MURI) grant on TOPological Flat bands fOr Correlated Electron systems (TOPFORCE) under the award number FA9550-22-1-0270.
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Publication:1. Day, R. P. et al. "Magnetoresistance and Anisotropic Spin Dynamics in Antiferromagnetic Semiconductor Eu5Sn2As6" arXiv:2407.06185. (2024) 2. Dahlbom, D. et al. "Langevin dynamics of generalized spins as SU(N) coherent states" Phy. Rev. B 106, 235154 (2022). 3. Rosa, P. et al. "Colossal magnetoresistance in a nonsymmorphic antiferromagnetic insulator" npj Quantum Mater. 5, 52 (2020). 4. Varnava N. et al. "Engineering magnetic topological insulators in Eu5M2X6 Zintl compounds" Phys. Rev. B 105, 235128 (2022)
