Strong spin-orbit interactions and weak antilocalization in carbon-doped p-type GaAs/AlxGa1−xAs heterostructures

B. Grbic (1) , R. Leturcq (2, 1) , T. Ihn (1) , K. Ensslin (1) , D. Reuter (3) , A.D. Wieck (3)

1 Laboratory for Solid State Physics [ETH Zürich]
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 RUB - Ruhr University Bochum = Ruhr-Universität Bochum

We present a comprehensive study of the low-field magnetoresistance in carbon doped p-type GaAs/AlGaAs heterostructures aiming at the investigation of spin–orbit interaction effects. The following signatures of exceptionally strong spin-orbit interactions are simultaneously observed: a beating in the Shubnikov-de Haas oscillations, a classical positive magnetoresistance due to the presence of the two spin-split subbands, and a weak anti-localization dip in the magnetoresistance. The spin-orbit induced splitting of the heavy hole subband at the Fermi level is determined to be around 30 % of the total Fermi energy. The phase coherence length of holes of around 2.5 µm at a temperature of 70 mK, extracted from weak anti-localization measurements, is promissing for the fabrication of phase-coherent p-type nanodevices

Domaines: Matière Condensée [cond-mat]

B. Grbic, R. Leturcq, T. Ihn, K. Ensslin, D. Reuter, et al.. Strong spin-orbit interactions and weak antilocalization in carbon-doped p-type GaAs/AlxGa1−xAs heterostructures. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008, 77 (12), pp.125312. ⟨10.1103/PhysRevB.77.125312⟩. ⟨hal-00357773⟩