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arXiv · 2408.03471

Quantum Spin Relaxation with THz Attempt Frequency in the 1/3-Fire, 2/3-Ice Ferrimagnet SmMn$_2$Ge$_2$

M. L. McLanahan·A. P. Ramirez
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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 SmMn$_2$Ge$_2$, 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 $E_B \approx 840$ $k_B$ 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.

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M. L. McLanahan, A. P. Ramirez. 2024-08-06. Quantum Spin Relaxation with THz Attempt Frequency in the 1/3-Fire, 2/3-Ice Ferrimagnet SmMn$_2$Ge$_2$. https://doi.org/10.1103/physrevmaterials.9.l051402

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