2, University of California, Los Angeles, Los Angeles, California, United States
Spintronics research based on topological insulators (TIs) has shown rapid progress during the past few years. Due to the strong spin-orbit coupling (SOC) and particularly the spin-momentum locked Dirac states on the surface, TIs are expected to be very promising materials for spintronic applications ranging from ultralow power memory/logic devices to new ultrafast computation technologies. In this talk, we will review the recent progress in the spintronics research based on TIs. First, we will go over the research on the detection of the spin-momentum locked surface states and the associated current-induced spin polarization on TIs, which provides a first step for the aftermentioned spintronic applications. Secondly, we will focus on the spin-orbit torque (SOT) research in different TI-based magnetic structures, including the magnetic TI bilayers and TI/ferro(or ferri-)magnet structures, and discuss the phenomena such as spin-torque ferromagnetic resonance and magnetization switching, which have significant implications on the potential memory/logic devices based on TIs. Thirdly, we will describe the spin pumping and spin to charge conversion effects in different TI/magnet structures, which show that TIs can serve as efficient spin detector/sensor in applications. Furthermore, we will elaborate the emerging topological antiferromagnetic research which combines TIs with antiferromagnetic materials. The merits of antiferromagnets, such as immunity to external field, absence from stray field, and their intrinsic ultrahigh-frequency dynamics, could bring many new topological physics and significantly enrich the landscape of spintronics research when they are combined with TIs. Finally, we will discuss the challenges and opportunities in the TI-based spintronics research and highlight the potential applications in ultralow-power and ultrafast-speed devices.