The neutral exciton transition (D0X) of Si-donor bound electrons is probed resonantly and the n-doped GaAs sample represents an ensemble of central spins.
We measure the electron spin dynamic at 4.2 K by spin noise spectroscopy. The experimental difference spectrum shows unambiguously the hyperfine coupling and contains contributions of transverse and longitudinal spin lifetime. The theoretical model for these spin noise powers is based on finite correlation time and explains the lineshapes. Further, the longitudinal spin lifetime is dependent on the excitation density and limited by the reorientation of nuclear spins.
The experiments yield for low frequencies the nuclear spin noise of the different isotopes. By that, we perform all optical NMR at low magnetic fields and thermal equilibrium and detect signatures of small quadrupolar interactions.
Person of contact
30167 Hannover