Effect of electron spin-spin exchange interaction on spin precession in coupled quantum well

Abstract

Room temperature gate modulation of electron spin relaxation time in (110)-oriented GaAs/AlGaAs quantum wells Appl. Phys. Lett. 97, 202102 (2010); 10.1063/1.3514675 Roles of the bias fields in the exchange interaction between the electron and hole spins in quantum wells Intersubband exchange interaction induced by optically excited electron spins in GaAs/AlGaAs quantum wells Appl. Phys. Lett. 94, 162104 (2009); 10.1063/1.3118584Room temperature electron spin coherence in telecom-wavelength quaternary quantum wells Electron spin-spin interaction in an asymmetric coupled quantum well (CQW) was investigated through electron spin-precession measurements. Precession (Larmor) frequencies from electrons localized in two CQWs were measured by means of polarization-and time-resolved photoluminescence measurements under a high magnetic field. At a low excitation power density, the Larmor frequency of the CQW was same as that of a single quantum well. The Larmor frequency of electron spin in one well was shifted to that in the other well as the excitation power density was increased. These experimental results are quantitatively explained by an exchange interaction between electrons localized in the two wells.