Direct Observation of the Electron Spin Relaxation Induced by Nuclei in Quantum Dots
Abstract
We have studied the electron spin relaxation in semiconductor InAs/GaAs quantum dots by time-resolved optical spectroscopy. The average spin polarization of the electrons in an ensemble of p-doped quantum dots decays down to 1/3 of its initial value with a characteristic time TΔ≈500 ps, which is attributed to the hyperfine interaction with randomly oriented nuclear spins. We show that this efficient electron spin relaxation mechanism can be suppressed by an external magnetic field as small as 100 mT.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 2005
- DOI:
- Bibcode:
- 2005PhRvL..94k6601B
- Keywords:
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- 72.25.Fe;
- 72.25.Rb;
- 73.21.La;
- 78.47.+p;
- Optical creation of spin polarized carriers;
- Spin relaxation and scattering;
- Quantum dots;
- Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter