Room-temperature spin–orbit magnetic fields in slightly misoriented (110) InGaAs/InAlAs multiple quantum wells

Abstract

Spin–orbit (SO) magnetic fields caused by the Dresselhaus SO interaction in slightly misoriented (110) InGaAs/InAlAs quantum wells (QWs) are investigated using the time-resolved and spatially resolved optical Kerr rotation technique. The Dresselhaus SO magnetic field is directed along the in-plane in the (001) QWs and along the out-of-plane in the (110) QWs. On the contrary, in QWs grown on a slightly misoriented (110) substrate, the out-of-plane and in-plane components of the Dresselhaus SO magnetic field coexist. In this study, the strong out-of-plane and the in-plane SO magnetic fields peculiar to the misoriented (110) InGaAs QWs are revealed at room temperature by analyzing spatially resolved diffusion-driven spin precession dynamics with a diagonally applied external magnetic field. Based on the scan position dependence of the spin precession frequency induced by the SO magnetic field, the simultaneous observations of the out-of-plane and the in-plane SO magnetic fields are achieved and Dresselhaus SO parameter is extracted to be 1.9×10−12 eV m. This value accounts for the scan position dependencies with various magnetic fields and reveals the reliability of the extracted SO parameter.