arXiv subjects

Hao Ou

Publications and source records attributed to Hao Ou.

3 recordsLinked to original sources

arXiv2026

Switchable Magnetoelectric Transport in Graphene via a Van der Waals Multiferroic

Electric and magnetic control of transport properties at atomic interfaces is central to the development of next generation electronics and spintronics. Van der Waals multiferroics materials that simultaneously host dielectric and magnetic orders down to the monolayer limit offer a promising platform for such interfacial control, yet the realization of electronic functionalities that exploit the unique attributes of van der Waals multiferroics has largely remained elusive. Here, we realize a van der Waals heterostructure comprising graphene and the multiferroic CuCrP2S6, enabling gate-switchable magnetoelectric transport in graphene, mediated by the multiferroic layer. The charge-neutrality resistance peak of graphene exhibits pronounced hysteresis arising from polarization flip in the multiferroic state. Application of an in-plane magnetic field shifts this peak in a polarization-dependent manner, revealing magnetic-field-induced polarization modulation a direct signature of the magnetoelectric effect. Furthermore, cooling the device under an applied electric field enables domain control of the multiferroic order, allowing reversible switching of the interfacial magnetoelectric transport. These results provide the first demonstration of interfacial magnetoelectric transport in a vdW heterostructure, and establish a pathway for engineering two-dimensional van der Waals interfaces for functional device applications.

cond-mat.mes-hall↗

arXiv2026

Strain Tuning of Orbital-Driven Giant Magnetoresistance in van der Waals ferrimagnet Mn$_3$Si$_2$Te$_6$

Strain engineering of magnetotransport offers a powerful strategy for uncovering emergent electronic and domain phenomena in quantum magnetic materials, while providing a promising pathway toward next-generation mechanically programmable spintronic technologies. Van der Waals magnets are particularly attractive in this context because their high crystallinity and mechanical flexibility allow exceptionally large, precisely controllable strain, enabling access to strain-induced functionalities unattainable in conventional solids. Here, we report systematic strain control of the van der Waals magnet Mn$_3$Si$_2$Te$_6$, which exhibits an unconventional colossal magnetoresistance whose microscopic origin remains under debate. We demonstrate in situ large-strain modulation of the electrical resistance in bulk crystals and show that the effect can be consistently explained by strain-tunable chiral orbital-current domains. Furthermore, measurements on exfoliated flake devices containing a single chiral domain reveal direct strain control of the electronic structure affected by orbital magnetic moment, establishing a unified microscopic mechanism for the unconventional colossal magnetoresistance. These results identify strain as an exceptionally effective control parameter for tailoring electronic and magnetic states in van der Waals magnets and provide a conceptual framework for realizing spin-straintronic functionalities based on orbital degrees of freedom.

cond-mat.mtrl-sci↗

arXiv2026

Piezomagnetic transport in van der Waals noncoplanar Antiferromagnets

The piezomagnetic effect-strain-induced linear modulation of magnetization, arises in magnets with broken time-reversal symmetry (BTRS), offering a pathway to bidirectional strain-based control of magnetism, which is an essential straintronic and spintronic functionality in solids. Metallic antiferromagnets with BTRS provide an ideal platform to study this effect through transport measurements, yet experimental demonstrations are limited. Van der Waals (vdW) nanomagnets, with their mechanical flexibility, are particularly promising for realizing large piezomagnetic responses and effective transport control. Here we demonstrate piezomagnetic control of electronic transport in nano-devices of the vdW antiferromagnets CoNb$_3$S$_6$ and CoTa$_3$S$_6$, archetypal vdW metals with BTRS that exhibit a spontaneous Hall effect. Applying uniaxial strain linearly modulates both the antiferromagnetic transition temperature and coercive field, consistent with strain-driven tuning of exchange coupling, key signatures of the piezomagnetic effect. Moreover, spontaneous Hall effect is controllable via strain, evidencing piezomagnetic tuning of Berry curvature and its associated geometric transport. These findings establish piezomagnetism as a powerful route to manipulate antiferromagnetic transport, opening avenues for straintronic and spintronic applications in vdW magnetic systems.

cond-mat.mes-hall↗