Summary: Long room-temperature electron spin lifetimes in bulk cubic
J. H. Buß,a J. Rudolph,a T. Schupp,b D. J. As,b K. Lischka,b and D. H¨agelea
aArbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universit¨at Bochum, 44801
bDepartment of Physics, University of Paderborn, Warburger Str. 100, 33098 Paderborn,
We report on very long electron spin lifetimes in cubic GaN measured by time-resolved Kerr-rotation-spectroscopy.
The spin coherence times with and without external magnetic field exceed 500 ps at room temperature, despite
a high n-type doping level of more than 1019
in the bulk sample under investigation. Our findings are
therefore highly relevant for spin optoelectronics in the blue wavelength regime. The spin lifetimes are found to
be almost temperature independent in accord with a prediction for degenerate electron gases of Dyakonov and
Perel from 1972. These results are discussed also in comparison to wurtzite GaN, which shows much shorter spin
lifetimes and a dependence of spin lifetimes on the spin orientation.
Keywords: spin relaxation, zincblende and wurtzite bulk GaN
The idea to incorporate the electron's spin degree of freedom into semiconductor-based electronics has stim-