Spintronics-based technology, which uses spins to represent and propagate information, holds promise to realize devices that surpass the current CMOS transistor technology in power, density and speed. For example, magnetic random-access memory (MRAM) based on magnetic tunnel junctions were identified as promising non-volatile memory but its use has been limited. A second generation MRAM-based on spin transfer torque has reduced currents. However, next generation MRAM based on pure spin currents may provide even more energy efficiency. My research is focused on developing power-efficient ways to generate, propagate and manipulate spins via pure spin currents. In order to develop such pure spin current technologies, the development of new materials such as topological insulators must come hand in hand with the development of new devices. In this talk, I will discuss (i) low damping ferromagnetic insulating thin films for achieving efficient spin current generation in spintronic devices, (ii) spin current generation in these films and large spin-charge interconversion in neighboring layers, (iii) spin interactions in ferromagnetic insulator/topological insulator heterostructures. Together these results lay the foundation for new energy-efficient pure spin current-based electronics.

Reference:

1. Li, P. et al. Topological Hall Effect in a Topological Insulator Interfaced with a Magnetic Insulator. Nano Lett. 21, 1, 84 (2021).

2. Li, P. et al. Switching magnetization utilizing topological surface state. Science Advances 5, eaaw3415 (2019).