arXiv subjects

Thi Ngoc Huyen Vu

Publications and source records attributed to Thi Ngoc Huyen Vu.

2 recordsLinked to original sources

arXiv2026

Microscopic Origin of Piezomagnetism in Mn$_3$Sn: A Dual Real- and $k$-Space Picture

We present a comprehensive first-principles study on the origin of the piezomagnetic effect in the non-collinear antiferromagnet Mn$_3$Sn, a material known for exhibiting a large anomalous Hall effect. We investigate strain-induced variations of electronic and magnetic states and elucidate the mechanism of the piezomagnetic effect from both real-space and momentum-space perspectives. In real space, the emergence of piezomagnetism is understood to arise from rotations of the magnetic moments at specific Mn sites, which directly couple to the strain. Through detailed electronic structure analysis, we identify the Fermi surfaces that play a crucial role in the emergence of piezomagnetism. Our results reveal that specific Fermi surface features undergo pseudo-degeneracy lifting under applied strain, which significantly contributes to the induced net magnetization. By combining these complementary real-space and momentum-space pictures, our dual-space analysis provides deep insight into the microscopic origins of strain-driven magnetization in Mn$_3$Sn.

cond-mat.mtrl-sci↗

arXiv2025

Investigation of Hole Dopability in Oxygen $2p$-Dominated Bands

The development of $p$-type oxide semiconductors remains impeded by the inherently low-lying valence-band maximum (VBM) dominated by O-2$p$ states. A prevailing approach to mitigate this limitation is to elevate the VBM by introducing cation states that hybridize with O-2$p$ orbitals or lie energetically above the O-2$p$ level. Nevertheless, the $p$-type oxides reported to date exhibit limited hole mobilities. To expand the search space, it is essential to accurately understand the intrinsic difficulty of introducing holes into O-2$p$-dominated bands. Accordingly, we evaluated 845 oxides to identify those in which holes can be doped into O-2$p$-dominated bands. Our high-throughput screening revealed CaCdO$_2$ as the only promising exemplar, in which the VBM is slightly hybridized with deep-lying Cd-3$d$ states. Our screening suggests that hole doping into O-2$p$-dominated bands is extremely difficult and thus reinforces the effectiveness of the traditional ``VBM-raising strategy.''

cond-mat.mtrl-sci↗