Control of electron spin–orbit anisotropy in pyramidal InAs quantum dots

• We investigate the spin–orbit anisotropy of InGaAs pyramidal dots under in-plane magnetic fields.
• We show that the anisotropy found in dots like those of PRL 104, 246801 (2010) is due to the interplay between Rashba and Dresselhaus spin–orbit interaction.
• We show that controlling the QD height and (In,Ga) alloying provides a powerful tool to tailor the spin–orbit anisotropy.

We investigate the electron spin–orbit interaction anisotropy of pyramidal InAs quantum dots using a fully three-dimensional Hamiltonian. The dependence of the spin–orbit interaction strength on the orientation of externally applied in-plane magnetic fields is consistent with recent experiments, and it can be explained from the interplay between Rashba and Dresselhaus spin–orbit terms in dots with asymmetric confinement. Based on this, we propose manipulating the dot composition and height as efficient means for controlling the spin–orbit anisotropy.