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.

Room-temperature spin relaxation rates resulting from the D’yakonov–Perel (DP) and Elliot–Yafet (EY) mechanisms were determined by combining microscopic and macroscopic Kerr rotation measurements in narrow-gap (001) InGaAs/InAlAs quantum wells (QWs). Two samples with different DP relaxation rate were compared and we found that EY relaxation rate (3.80 GHz) was approximately double the value of the average DP relaxation rate even in the asymmetric QWs with large spin-orbit parameters. We also found that the anisotropy of spin relaxation time owing to the DP mechanism is weakened significantly in the system in which the EY mechanism dominates the spin relaxation.

Recently, we directly observed the out-of-plane Dresselhaus spin–orbit (SO) interaction field and extracted the SO coefficient β from InGaAs (110) quantum wells (QWs). However, the extracted β was much larger than that of the (001) QWs, which yielded an in-plane Dresselhaus SO field. In this study, we perform Monte-Carlo simulations and reproduce the results of time-resolved and spatiotemporally resolved Kerr rotation measurements in InGaAs (110) QWs. The results conclusively show that InGaAs (110) QWs have a strong out-of-plane Dresselhaus SO field as compared with (001) QWs.