2026, Dynamic Control of Heterointerface Coupling in Magnetic van der Waals Heterostructures via Pressure Engineering, ACS Nano.
2026, Dynamic Control of Heterointerface Coupling in Magnetic van der Waals Heterostructures via Pressure Engineering, ACS Nano.
Abstract:
Moiré excitons in twisted transition metal dichalcogenides form a highly tunable and correlated system, whose valley pseudospins with long coherence establish them as a promising platform for valleytronics. However, their inherent valley degeneracy remains largely intact, limiting deterministic control despite highly tunable exciton bands and strong interaction effects. Here, we construct a twisted WSe2/VSe2 van der Waals heterostructure by coupling twisted WSe2homobilayers with ferromagnetic 1T-VSe2, and systematically investigate the magnetic proximity effect (MPE) as a direct mechanism for manipulate valley pseudospins through valley degeneracy lifting. photoluminescence measurements reveal that interfacial coupling with VSe2 deepens the moiré potential by ∼18% (from 45.33 to 53.57 meV). Furthermore, theMPE gives rise to a zero-field valley splitting of ∼0.9 meV, corresponding to an effective magnetic field of ∼1.71 T. This coupling elevates the average Landé g-factor of moiré excitons to -9.05, far exceeding that of the isolated homobilayers(-5.7), and enhances the magnetic-field response of valley polarization by approximately 300 %. Temperature-dependent studies further reveal that the thermal evolution of valley polarization is governed by the spin thermodynamics of the ferromagnetic layer, marked by its sharp decrease with rising temperature. These findings establish the magnetic proximity modulation as a powerful and deterministic strategies to control valley pseudospins on a moiré exciton platform, paving the way for the development of valleytronics and quantum spin devices.
Keywords: Heterointerface coupling, van der Waals heterostructures, high pressure, exciton transition, phonon sideband, electron-phonon coupling.
Link: https://pubs.acs.org/doi/full/10.1021/acsnano.6c01181
