Tunable spin and orbital polarization in SrTiO3-based heterostructures. (9th October 2019)

• Record Type: Journal Article
• Authors: Ho, Cong Son; Kong, Weilong; Yang, Ming; Rusydi, Andrivo; Jalil, Mansoor B A
• Is Part Of: New journal of physics. Volume 21:Number 10(2019:Oct.)
• Publication Date: 2019-10-09
• Subjects: Rashba splitting -- oxides interface -- k.p method -- multi-orbital; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/ab4735
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We formulate the effective Hamiltonian of Rashba spin–orbit coupling (RSOC) in LaAlO 3 / SrTiO 3 (LAO/STO) heterostructures. We derive analytical expressions of properties, e.g. Rashba parameter, effective mass, band edge energy and orbital occupancy, as functions of material and tunable heterostructure parameters. While linear RSOC is dominant around the Γ-point, cubic RSOC becomes significant at the higher-energy anti-crossing region. We find that linear RSOC stems from the structural inversion asymmetry (SIA), while the cubic term is induced by both SIA and bulk asymmetry. Furthermore, the SOC strength shows a striking dependence on the tunable heterostructure parameters such as STO thickness and the interfacial electric field which is ascribed to the quantum confinement effect near the LAO/STO interface. The calculated values of the linear and cubic RSOC are in agreement with previous experimental results.