title: Spin-relaxation anisotropy in a GaAs quantum dot.
abstract: We report that the electron spin-relaxation time T_{1} in a GaAs quantum dot with a spin-1/2 ground state has a 180° periodicity in the orientation of the in-plane magnetic field. This periodicity has been predicted for circular dots as being due to the interplay of Rashba and Dresselhaus spin orbit contributions. Different from this prediction, we find that the extrema in the T_{1} do not occur when the magnetic field is along the [110] and [11[over ¯]0] crystallographic directions. This deviation is attributed to an elliptical dot confining potential. The T_{1} varies by more than 1 order of magnitude when rotating a 3 T field, reaching about 80 ms for the optimal angle. We infer from the data that in our device the signs of the Rashba and Dresselhaus constants are opposite.
authors.affiliation: Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Scarlino
authors.affiliation: Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Kawakami
authors.affiliation: RIKEN Center for Emergent Matter Science, Wako-shi, Saitama 351-0198, Japan and Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 84511 Bratislava, Slovakia.
authors.forename: P
authors.initials: P
authors.lastname: Stano
authors.affiliation: Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Shafiei
authors.affiliation: Solid State Physics Laboratory, ETH Zurich, Schafmattstrasse 16, 8093 Zurich, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Reichl
authors.affiliation: Solid State Physics Laboratory, ETH Zurich, Schafmattstrasse 16, 8093 Zurich, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Wegscheider
authors.affiliation: Kavli Institute of Nanoscience, TU Delft, Lorentzweg 1, 2628 CJ Delft, Netherlands.
authors.forename: L M K
authors.initials: LM
authors.lastname: Vandersypen