The magnetoresistance at temperatures below 20 K in an $n\text{-InSb}/{\text{In}}_{0.85}{\text{Al}}_{0.15}\text{Sb}$ two-dimensional electron system is studied and described in terms of antilocalization due to quantum interference under strong spin-orbit interaction. The spin-orbit interaction coefficients are extracted by fitting the magnetoresistance data to an antilocalization theory distinguishing the Rashba and Dresselhaus contributions. A good agreement between magnetoresistance data and theory suggests a Rashba coefficient $\left|\alpha \right|\approx 0.03\text{eV}\text{Å}$ and a Dresselhaus coefficient $\gamma \approx 490\text{eV}{\text{Å}}^3$. A strong contribution from the Dresselhaus term leads to pronounced anisotropy in the energy splitting induced by spin-orbit interaction in the two-dimensional electron dispersion.

• Received 10 July 2009

DOI:https://doi.org/10.1103/PhysRevB.81.075303