posted on 2023-12-19, 17:05authored byGuo-Dong Zhao, Weida Fu, Yongchang Li, Xingen Liu, Fanhao Jia, Tao Hu, Wei Ren
Due
to the lack of inversion symmetry and the discovery of room-temperature
ferromagnetism, two-dimensional semiconducting vanadium-based van
der Waals transition-metal dichalcogenides (V-TMDs) are drawing attention
for their possible application in spintronics and valleytronics. Here,
we show the functional properties enriched by the broken inversion,
out-of-plane mirror, and time-reversal symmetries of Janus H–VXY TMDs (X, Y = S, Se,
Te). By first-principles calculations, we reveal the intrinsic xy easy-plane magnetism of the Janus vanadium-based TMD
monolayers and systematically study their hidden valley polarization
and giant magneto band structure. Their strong nearest-neighbor exchange
strengths lead to near-room-temperature magnetic phase transitions.
The Janus H–VXY system also exhibits piezoelectricity
with nonzero e31 and e21. Interestingly, it is found that the right-handed Dzyaloshinskii–Moriya
interaction has nonzero in-plane components in our Janus system, with
fluctuating magnitudes determined by competence between relaxed bond-angle
and atomic index of ligands.