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arXiv · 2010.07947

Spectroscopic fingerprints of gapped quantum spin liquids, both conventional and fractonic

Rahul M. Nandkishore·Wonjune Choi·Yong Baek Kim
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Abstract

We explain how gapped quantum spin liquids, both conventional and 'fractonic', may be unambiguously diagnosed experimentally using the technique of multidimensional coherent spectroscopy. 'Conventional' gapped quantum spin liquids (e.g. $Z_2$ spin liquid) do not have clear signatures in linear response, but do have clear fingerprints in non-linear response, accessible through the already existing experimental technique of two dimensional coherent spectroscopy. Type I fracton phases (e.g. X-cube) are (surprisingly) even easier to distinguish, with strongly suggestive features even in linear response, and unambiguous signatures in non-linear response. Type II fracton systems, like Haah's code, are most subtle, and may require consideration of high order non-linear response for unambiguous diagnosis.

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Rahul M. Nandkishore, Wonjune Choi, Yong Baek Kim. 2020-10-15. Spectroscopic fingerprints of gapped quantum spin liquids, both conventional and fractonic. https://doi.org/10.1103/physrevresearch.3.013254

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