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arXiv · 2304.10823

Theory of absorption in a frustrated spin gap system ${\rm SrCu_2(BO_3)_2}$

Shin Miyahara
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Abstract

We achieve a comprehensive understanding of the magnetic excitations observed by electric spin resonance and far-infrared spectroscopy in a frustrated spin gap system ${\rm SrCu_2(BO_3)_2}$ by considering the effects of magnetoelectric couplings and Dzyaloshinskii-Moriya interactions in the Shastry-Sutherland model. The transitions from the dimer singlet ground state to the triplon and the bound states of two triplons are electroactive through the magnetoelectric couplings, even in the Shastry-Sutherland Heisenberg model. The results indicate that an electro-triplon and a novel electroactive magnetic excitation, as with an electromagnon in the multiferroics, can be realized in the conventional spin-gapped singlet and anomalous spin-liquid states. Clarifying these electroactive magnetic excitations in various spin systems will help analyze a broad range of quantum magnets, {\it e.g.}, quantum spin liquids and spin nematics.

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Shin Miyahara. 2023-04-21. Theory of absorption in a frustrated spin gap system ${\rm SrCu_2(BO_3)_2}$. https://arxiv.org/abs/2304.10823

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