Prabhakar, S., Raynolds, J.E., Melnik, R.
Physical Review B, 84 (15), 155208, 2011
We study the variation in the Lande g factor of electron spins induced by both anisotropic gate potentials and magnetic fields in InAs quantum dots for possible implementation toward solid-state quantum computing. In this paper, we present analytical expressions and numerical simulations of the variation in the Lande g factor for both isotropic and anisotropic quantum dots. Using both analytical techniques and numerical simulations, we show that the Rashba spin-orbit coupling has a major contribution in the variation of the g factor with electric fields before the regime, where level crossing or anticrossing occurs. In particular, the electric-field tunability is shown to cover a wide range of g factor through strong Rashba spin-orbit interaction. Another major result of this paper is that the anisotropic gate potential gives quenching effect in the orbital angular momentum that reduces the variation in the E-field and B-field tunability of the g factor if the area of the symmetric and asymmetric quantum dots is held constant. We identify level crossings and anticrossings of the electron states in the variation of the Lande g factor. We model the wave functions of electron spins and estimate the size of the anticrossing for the spin states vertical bar 0, -1, + 1/2 > and vertical bar 0,0, -1/2 > corresponding to a quantum dot that has been recently studied experimentally [Takahashi et al., Phys. Rev. Lett. 104, 246801 (2010)].