Speaker
Description
A computational study is presented with the aim to mimic different experimental approaches to tune the magnetic interactions in two-dimensional van der Waals magnets. The tensorial exchange interactions [1] among all relevant atomic pairs are evaluated for CrGeSe$_3$, CrGeTe$_3$, and Janus Cr$_2$Ge$_2$(Se,Te)$_3$ monolayers and their dependence is analyzed on different external parameters, such as biaxial and uniaxial strain, as well as gate voltage. Particular attention is paid to interactions that emerge or vanish due to changes in the system’s symmetry, especially under uniaxial strain and gate voltage. It is found that biaxial and uniaxial strains significantly modify the isotropic exchange couplings, which can lead to a transition from a ferromagnetic to an antiferromagnetic phase, while a gate voltage induces Dzyaloshinskii–Moriya interactions, forming a vortex pattern whose chirality is determined by the sign of the electric field. The electric dipole moment of the Janus material turns out to be large, raising the possibility of multiferroic behavior [2].
References
[1] Gabriel Martínez-Carracedo, László Oroszlány, Amador García-Fuente, Bendegúz Nyári, László Udvardi, László Szunyogh, and Jaime Ferrer, Phys. Rev. B 108, 114418 (2023)
[2] Gabriel Martínez-Carracedo, Amador García-Fuente, László Oroszlány, László Szunyogh, Jaime Ferrer, Phys. Rev. B 110, 184406 (2024)
