Quantum Spin Relaxation with THz Attempt Frequency in the 1/3-Fire, 2/3-Ice Ferrimagnet SmMn$_2$Ge$_2$
Abstract
Ferrimagnets in which half the spins are disordered and half ordered, so-called half-fire, half-ice state, have been advanced theoretically as a route towards realizing exotic magnetic ground states. Here we demonstrate novel single-spin resonance in SmMnGe, a 1/3-fire, 2/3-ice material. Using ac-susceptibility in the frequency range 0.1 Hz - 1 kHz we find a Debye-like resonance with Orbach relaxation temperature dependence, yielding an energy barrier and attempt frequencies in the THz range. These quantities strongly suggest single-spin relaxation among paramagnetic Sm spins where the flipping field is provided by the FM-ordered Mn spins at domain boundaries, a direct outcome of the 1/3-fire, 2/3-ice state.
Keywords
Cite
@article{arxiv.2408.03471,
title = {Quantum Spin Relaxation with THz Attempt Frequency in the 1/3-Fire, 2/3-Ice Ferrimagnet SmMn$_2$Ge$_2$},
author = {M. L. McLanahan and A. P. Ramirez},
journal= {arXiv preprint arXiv:2408.03471},
year = {2025}
}
Comments
Main text: 18 pages, 5 figures. Supplemental: 7 pages, 5 figures; V2: Revised introduction and discussion. Results unchanged