Electronic control of combined spin-orbit and magnetic exchange coupling in graphene van der Waals-heterostructures (CombSOC)

点击翻译按钮获取中文摘要

This project aims to combine spin-orbit coupling (SOC) and magnetic proximity effects in van der Waals heterostructures to imprint tailored and electrically tunable spin polarizations in the band structure of graphene. In undoped (2D magnet/graphene/2D SOC material) heterotrilayers, CombSOC envisions to experimentally demonstrate the in-plane magnetic anisotropies and topological gap openings close to the charge neutrality point of graphene arising from the combined proximity, and explore whether their strength can be controlled through external stimuli, such as an externally applied electric displacement field. By comparison, in charge transfer doped heterotrilayers, CombSOC seeks to reveal the induced spin polarizations far away from the charge neutrality point and their impact on emergent collective spin and charge excitations in the highly doped graphene layer. The double-proximitized graphene will be investigated by complementary electronic and optoelectronic spectroscopies. While magnetotransport experiments shall reveal the magnetic anisotropies and topological gap openings near the charge neutrality point, spin valve measurements will yield the spin lifetime anisotropy. Moreover, spin-dependent tunneling spectroscopy is utilized to quantify the spin polarizations away from the charge neutrality point. Using a time-resolved, resonant photocurrent spectroscopy in the near and mid-infrared regime, the symmetries and dynamics of the anisotropic photogalvanic currents, which are linked to the spin-dependent interband transitions in the proximitized graphene, will be fundamentally characterized.