Raith, Martin and Stano, Peter and Fabian, Jaroslav
Theory of spin relaxation in two-electron laterally coupled Si/SiGe quantum dots.
Physical Review B (PRB) 86 (20), p. 205321.
Highly accurate numerical results of phonon-induced two-electron spin relaxation in silicon double quantum dots are presented. The relaxation, enabled by spin-orbit coupling and the nuclei of 29Si (natural or purified abundance), is investigated for experimentally relevant parameters, the interdot coupling, the magnetic field magnitude and orientation, and the detuning. We calculate relaxation rates for zero and finite temperatures (100 mK), concluding that our findings for zero temperature remain qualitatively valid also for 100 mK. We confirm the same anisotropic switch of the axis of prolonged spin lifetime with varying detuning as recently predicted in GaAs. Conditions for possibly hyperfine-dominated relaxation are much more stringent in Si than in GaAs. For experimentally relevant regimes, the spin-orbit coupling, although weak, is the dominant contribution, yielding anisotropic relaxation rates of at least two orders of magnitude lower than in GaAs.
|Date:||28 November 2012|
|Institutions:|| Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Jaroslav Fabian|
|72.25.Rb, 03.67.Lx, 71.70.Ej, 73.21.La ||PACS|
|Keywords:||quantum dots, silicon, spin relaxation, singlet, triplet|
|Subjects:||500 Science > 530 Physics|
|Refereed:||Yes, this version has been refereed|
|Created at the University of Regensburg:||Yes|
Dipl.-Phys. Martin Raith
|Deposited On:||02 Jul 2012 12:53|
|Last Modified:||03 Dec 2012 09:26|