Sensitively temperature-dependent spin-orbit coupling in SrIrO₃ thin films

Spin-orbit coupling induces nonperturbation effects in many recently developed novel fields including topological insulators and spin-orbit assistant Mott insulators. In this study, strongly temperature-dependent spin-orbit coupling is observed at a low temperature in a 5d strongly correlated compound, SrIrO₃. With an increase in temperature, the rate of increase in Rashba coefficient is about 30-45%/K, nearly 100 times over that observed in semiconductor heterostructures. Microscopically, the large increase in Rashba coefficient is attributed to the significant evolution of effective Landé g factor with temperature, whose mechanism is discussed qualitatively. Sensitively temperature-dependent spin-orbit coupling in SrIrO₃ might be applied in spintronic devices.