Extracting strength of spin-orbit coupling in InAs-Al heterostructures: Implications for topological superconductivity

Topological superconductivity is expected to emerge in materials with a strong spin-orbit coupling. Beyond the realization of topological superconductivity it is important to control the topological-trivial phase transition as well. This can be achieved through a gate tunable spin-orbit coupling in epitaxially grown two-dimensional InAs-Al heterostrcutres. Here, we discuss extracting the strength of linear Dresselhaus and Rashba spin-orbit coupling terms from magnetoconductivity measurements which manifest as weak localization or antilocalization signatures. A fully quantum mechanical model is used to describe the electronic states and the interference effects resulting from scattering loops in the presence of an external out-of-plane magnetic field. The extracted experimental results are then compared with the solutions of the 8-band Kane model for Zinc blende crystals with a reduced symmetry in the growth direction. We then discuss the symmetry and the interplay of Dresselhaus and Rashba spin-orbit coupling terms as well as the effect of an in-plane magnetic field in realizing topological superconductivity.