Interface Physics and Applications in Topological Insulator-based Magnetic Heterostructures
Abstract
Th e proposed research will create novel TI- based magnetic heteostructures, and investigate their properties as well as their related interfacial physics. The proposed research will carry out three main tasks: ( 1) Growth of TI/magnetic heterostructures for understanding the fundamental physics of both the spin-orbit interaction and the magnetic exchange coupling across the interface of TI-based magnetic heterostructures. These will include: Prepare high-quality TI/FMI, TI/AFM and Tl/ AFM/FM heterostructures with atomically sharp interfaces by using molecular beam epitaxy (MBE); Design modulation Cr-doped TI/magnetic TI/TI systems with accurate magnetic doping profiles in order to understand the topological nature of the giant SOT and its relations with topological surface spin-momentum locking mechanism and magnetic interaction range; Fabricate double-gated devices and realize electric-field-controlled SOT and magnetization switching in TI/magnetic TI heterostructures; Perform a comprehensive study to find the suitable (magnetic) TI/FMI (e.g., YIG) heterostructurcs for the realizations of high TC and giant SOT at room temperature. (2) Understanding of interface effects of SOC and SOT and enhancement of the TI interface-assisted giant SOT for room-temperature operations. These will include: Use the state-of-art magneto-transport measurements and non-linear magneto-optical Kerr effects (MOKE) to investigate the interfacial magnetic exchange interaction and the spin-polarized surface current in the TI/FMI system; Carry out extensive studies to investigate the effect of AFM materials on the adjacent TI band topology as well as the effects of TI s giant SOT on the AFM-based phenomena; Design and construct TI/ AFM/FM trilayer structures for enhancing the spin transfer efficiency and realizing possible magnetiz.ation switching in ferromagnetic materials mediated by the AFM layer; Apply ultrafast pump-probe optical technique to study and characterize the dynamics of SOT in TI/AFM (either through FM coupling or direct read out by optical means). (3) Investigation of other uncovered properties related to SOC. These will include: Determining THz properties of TI/ AFM spin waves; Study SOT-induced coherent spin-wave or superfluid spin transport dynamics in TI/FM (AFM) heterostructures; corroborate time and frequency domain data; Further investigate other uncovered high-energy physics properties related to relativistic SOC using our materials and structural platforms established in Task I.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510561
Entities
People
- Kang L. Wang
Organizations
- Army Contracting Command
- United States Army
- University of California, Los Angeles