| Full text | |
| Author(s): |
Henriques, A. B.
[1]
;
Schwan, A.
[2]
;
Varwig, S.
[2]
;
Maia, A. D. B.
[1]
;
Quivy, A. A.
[1]
;
Yakovlev, D. R.
[2]
;
Bayer, M.
[2]
Total Authors: 7
|
| Affiliation: | [1] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo - Brazil
[2] Tech Univ Dortmund, D-44221 Dortmund - Germany
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Physical Review B; v. 86, n. 11 SEP 28 2012. |
| Web of Science Citations: | 4 |
| Abstract | |
Spin coherence generation in an ensemble of negatively charged (In,Ga)As/GaAs quantum dots was investigated by picosecond time-resolved pump-probe spectroscopy measuring ellipticity. Robust coherence of the ground-state electron spins is generated by pumping excited charged exciton (trion) states. The phase of the coherent state, as evidenced by the spin ensemble precession about an external magnetic field, varies relative to spin coherence generation resonant with the ground state. The phase variation depends on the pump photon energy. It is determined by (a) pumping dominantly either singlet or triplet excited states, leading to a phase inversion, and (b) the subsequent carrier relaxation into the ground states. From the dependence of the precession phase and the measured g factors, information about the quantum dot shell splitting and the exchange energy splitting between triplet and singlet states can be extracted in the ensemble. (AU) | |
| FAPESP's process: | 10/10452-8 - Multiple harmonic spectroscopy, spin orientation and instantaneous magnetization using light |
| Grantee: | Andre Bohomoletz Henriques |
| Support Opportunities: | Regular Research Grants |