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arXiv · 2001.07219

Linear magneto-electric phase in ultrathin MnPS$_{3}$ probed by optical second harmonic generation

H. Chu·C. J. Roh·J. O. Island·C. Li·S. Lee·J. Chen·J. G. Park·A. F. Young·J. S. Lee·D. Hsieh
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Abstract

The transition metal thiophosphates $M$PS$_3$ ($M$ = Mn, Fe, Ni) are a class of van der Waals stacked insulating antiferromagnets that can be exfoliated down to the ultrathin limit. MnPS$_3$ is particularly interesting because its N$\acute{\textrm{e}}$el ordered state breaks both spatial-inversion and time-reversal symmetries, allowing for a linear magneto-electric phase that is rare among van der Waals materials. However, it is unknown whether this unique magnetic structure of bulk MnPS$_3$ remains stable in the ultrathin limit. Using optical second harmonic generation rotational anisotropy, we show that long-range linear magneto-electric type N$\acute{\textrm{e}}$el order in MnPS$_3$ persists down to at least 5.3 nm thickness. However an unusual mirror symmetry breaking develops in ultrathin samples on SiO$_2$ substrates that is absent in bulk materials, which is likely related to substrate induced strain.

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H. Chu, C. J. Roh, J. O. Island, C. Li, S. Lee, J. Chen, J. G. Park, A. F. Young, J. S. Lee, D. Hsieh. 2020-01-20. Linear magneto-electric phase in ultrathin MnPS$_{3}$ probed by optical second harmonic generation. https://doi.org/10.1103/physrevlett.124.027601

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