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arXiv · 2103.07100

Implications of second harmonic generation for hidden order in Sr$_2$CuO$_2$Cl$_2$

A. de la Torre·S. Di Matteo·D. Hsieh·M. R. Norman
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Abstract

Sr$_2$CuO$_2$Cl$_2$ (SCOC) is a model undoped cuprate with $I4/mmm$ crystallographic symmetry, and a simple magnetic space group $C_Amca$ with associated magnetic point group $mmm1'$. However, recent second harmonic spectroscopy in the antiferromagnetic phase has challenged this picture, suggesting instead a magnetic point group $4/mm'm'$ that co-exists with the antiferromagnetism and breaks the two orthogonal mirror planes containing the tetragonal $c$-axis. Here, we analyze the symmetry of SCOC in light of the second harmonic results, and discuss possible ground states that are consistent with the data.

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A. de la Torre, S. Di Matteo, D. Hsieh, M. R. Norman. 2021-03-12. Implications of second harmonic generation for hidden order in Sr$_2$CuO$_2$Cl$_2$. https://doi.org/10.1103/physrevb.104.035138

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