K. Seo

Efficient spin relaxation in InGaN/GaN and InGaN/GaMnN quantum wells : An obstacle to spin detection

Transient magneto-optical spectroscopy of InGaNGaN and InGaNGaMnN quantum wells reveals a spin relaxation process with a characteristic time of 50 ps. We show that the observed spin relaxation is m ...

Spin dynamics in a diluted magnetic semiconductor quantum well studied by pump-probe absorption spectroscopy: Magnetic-field-induced suppression of electron-spin relaxation

Exciton spin dynamics is studied in a diluted magnetic semiconductor quantum well of Cd0.95Mn0.05Te by pump-probe absorption spectroscopy under magnetic fields. The time dependences of the saturated absorbance for the higher- and lower-energy spin states of heavy-hole (hh) excitons clarify the following exciton-spin relaxation process in magnetic fields: ultrafast hh-spin relaxation with the formation of dark excitons and subsequent electron-spin relaxation. The electron-spin relaxation due to the s-d exchange mechanism involving Mn spins is suppressed in a high magnetic field by field-induced pinning of the Mn spins.

Ultrafast Exciton Spin Dynamics in Cd1−xMnxTe Quantum Wells

Dynamics of spin‐polarized excitons has been studied in diluted magnetic semiconductor quantum wells by femto‐second pump‐probe spectroscopy in magnetic fields. Transient processes of injection and spin relaxation of excitons are measured in the quantum wells. The injection time and the spin‐flip time of excitons are obtained as 5 ps and 41 ps, respectively.