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arXiv · 2608.23683

Raman Circular Dichroism Reveals Higher-Order Quantum Geometry of Magnons

Yong Chan Kim·Youngsu Choi·Kwang-Yong Choi·Kyusung Hwang
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Abstract

We develop a gauge-invariant framework that relates two-magnon Raman circular dichroism (RCD) to higher-order magnon quantum geometry. In the magnon band basis, the Raman operator decomposes into interband Berry connections, their covariant derivatives, and products of successive connections, generating higher-order, multi-state geometric tensors beyond the conventional single-band quantum metric and Berry curvature. Applying this framework to a field-polarized Kitaev magnet, we show that higher-order geometric tensors govern the dichroic response. Our results establish RCD as a spectroscopic probe of generalized magnon quantum geometry.

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Yong Chan Kim, Youngsu Choi, Kwang-Yong Choi, Kyusung Hwang. 2026-08-24. Raman Circular Dichroism Reveals Higher-Order Quantum Geometry of Magnons. https://arxiv.org/abs/2608.23683

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