Spin Transport And Spin Relaxation In Ge/Si Quantum Dots

摘要

The spin relaxation for localized hole state in single Ge quantum dot and for hole tunneling between two coupled quantum dots were investigated theoretically. The time of spin relaxation due to acoustic phonon coupling (direct one-phonon processes) is ~ 10–5s at temperature T=4K. A new mechanism of spin dephasing due to the structure-inversion asymmetry (SIA) of Ge quantum dot is offered. At the tunneling the angular momentum of hole is turned at the small angle and this provokes the spin flip after several events of tunneling. Simple estimations of spin relaxation caused by SIA mechanism give τ~10–5s.