Anisotropic electron g-factor in quantum dots with spin-orbit interaction

We study the variation in the Land$\acute{\text{e}}$ g-factor of electron spins induced by both anisotropic gate potentials and magnetic fields in InAs quantum dots for possible implementation towards solid state quantum computing. In this paper, we present analytical expressions and numerical simulations of the variation in the Land$\acute{\text{e}}$ g-factor for both isotropic and anisotropic quantum dots. Using both analytical techniques and numerical simulations, we show ...

We have investigated the electronic properties of elliptical quantum dots in a perpendicular external magnetic field, and in the presence of the Rashba spin-orbit interaction. Our work indicates that the Fock-Darwin spectra display strong signature of Rashba spin-orbit coupling even for a low magnetic field, as the anisotropy of the quantum dot is increased. An explanation of this pronounced effect with respect to the anisotropy is presented. The strong spin-orbit coupling ef...

We present angle-dependent measurements of the effective g-factor g* in a Ge-Si core-shell nanowire quantum dot. g* is found to be maximum when the magnetic field is pointing perpendicular to both the nanowire and the electric field induced by local gates. Alignment of the magnetic field with the electric field reduces g* significantly. g* is almost completely quenched when the magnetic field is aligned with the nanowire axis. These findings confirm recent calculations, where...

Non-charge based logic in single-hole spin of semiconductor quantum dots (QDs) can be controlled by anisotropic gate potentials providing a notion for making next generation solid-state quantum devices. In this study, we investigate the isotropic and anisotropic behavior of phonon mediated spin relaxation of heavy-hole spin hot spots in QDs. For the electron spin in isotropic QDs, hot spots are known to be always present due to the Rashba spin-orbit coupling. But for heavy ho...

We study theoretically phonon-assisted spin relaxation of an electron confined in an elliptical quantum dot (QD) subjected to a tilted magnetic field. In the presence of both Rashba and Dresselhaus spin-orbit terms, the relaxation rate is anisotropic with respect to the in-plane field orientation. This anisotropy originates from the interference, at nonzero tilt angle, between the two spin-orbit terms. We show that, in a narrow range of magnetic field orientations, the relaxa...

The knowledge of electron and hole g-factors, their control and engineering are key for the usage of the spin degree of freedom for information processing in solid state systems. The electronic g-factor will be materials dependent, the effect being larger for materials with large spin-orbit coupling. Since electrons can be individually trapped into quantum dots in a controllable manner, they may represent a good platform for the implementation of quantum information processin...

In this paper, a detailed analysis of anisotropic effects on the phonon induced spin relaxation rate in III-V semiconductor quantum dots (QDs) is carried out. We show that the accidental degeneracy due to level crossing between the first and second excited states of opposite electron spin states in both isotropic and anisotropic QDs can be manipulated with the application of externally applied gate potentials. In particular, anisotropic gate potentials enhance the phonon medi...

We investigate theoretically how the spin-orbit Dresselhaus and Rashba effects influence the electronic structure of quasi-one-dimensional semiconductor quantum dots, similar to those that can be formed inside semiconductor nanorods. We calculate electronic energy levels, eigen-functions, and effective g-factors for coupled, double dots made out of different materials, especially GaAs and InSb. We show that by choosing the form of the lateral confinement, the contributions of...

We show that the g-factor and the spin-flip time T_{1} of a heterojunction quantum dot is very sensitive to the band-bending interface electric field even in the absence of wave function penetration into the barrier. When this electric field is of the order of 10^{5} V/cm, g and T_{1} show high sensitivity to dot radius and magnetic field arising from the interplay between Rashba and Dresselhaus spin-orbit interactions. This result opens new possibilities for the design of a ...

We present calculations of the g factors for the lower conductance steps of 3D hole quantum wires. Our results prove that the anisotropy with magnetic field orientation, relative to the wire, originates in the Rashba spin-orbit coupling. We also analyze the relevance of the deformation, as the wire evolves from 3D towards a flat 2D geometry. For high enough wire deformations, the perpendicular g factors are greatly quenched by the Rashba interaction. On the contrary, parallel...