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arXiv · 2209.09853

Detecting symmetry fractionalization in gapped quantum spin liquids by magnetic impurities

Shuangyuan Lu·Yuan-Ming Lu
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Abstract

We study the Kondo effect of spin-1/2 magnetic impurities in gapped Z2 spin liquids on two-dimensional lattices. We find that if the impurity is placed at a high-symmetry location, a nontrivial spinon fractionalization class of the impurity site symmetry group will necessarily lead to a non-Kramers doublet in the Kondo screening regime, protected by associated crystalline symmetries. This is in sharp contrast to a featureless screening phase in the usual Kondo effect. We demonstrate this symmetry-protected topological degeneracy by an exactly solvable model and by the large-N theory. Based on this effect, we discuss how thermodynamic measurements in the limit of dilute magnetic impurities can be used to detect symmetry fractionalization in gapped Z2 spin liquids.

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Shuangyuan Lu, Yuan-Ming Lu. 2022-09-20. Detecting symmetry fractionalization in gapped quantum spin liquids by magnetic impurities. https://doi.org/10.1103/physrevb.110.l100401

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