Consequences of the thermal dependence of spin orbit coupling in semiconductors

The $\vec{k}.\vec{p}$ perturbation theory in semiconductor modifies some spin related parameters of the semi-conducting system. Furthermore, renormalization of the Kane model parameters occurs when temperature appears in the scenario. In this paper, we have analysed the consequences of this renormalized Kane parameters on some spin transport issues. It is noteworthy to study that the temperature corrected scenario, explained here can open up a new direction towards the spin calorimetric applications in semiconductors.Comment: To appear in Solid State Communicatio

Effect of spin rotation coupling on spin transport

We have studied the spin rotation coupling(SRC) as an ingredient to explain different spin related issues. This special kind of coupling can play the role of a Dresselhaus like coupling in certain conditions. Consequently, one can control the spin splitting, induced by the Dresselhaus like term, which is unusual in semiconductor heterostucture. Within this framework, we also study the renormalization of the spin dependent electric field and spin current due to the $\vec{k} . \vec{p}$ perturbation, by taking into account the interband mixing in the rotating system. In this paper we predict the enhancement of the spin dependent electric field resulting from the renormalized spin rotation coupling. The renormalization factor of the spin electric field is different from that of the SRC or Zeeman coupling. The effect of renormalized SRC on spin current and Berry curvature is also studied. Interestingly, in presence of this SRC induced SOC it is possible to describe spin splitting as well as spin galvanic effect in semiconductors.Comment: 12 pages, no figures, Accepted for publication in Annals of Physic

The geometric phase and the geometrodynamics of relativistic electron vortex beams

We have studied here the geometrodynamics of relativistic electron vortex beams from the perspective of the geometric phase associated with the scalar electron encircling the vortex line. It is pointed out that the electron vortex beam carrying orbital angular momentum is a natural consequence of the skyrmion model of a fermion. This follows from the quantization procedure of a fermion in the framework of Nelson's stochastic mechanics when a direction vector (vortex line) is introduced to depict the spin degrees of freedom. In this formalism a fermion is depicted as a scalar particle encircling a vortex line. It is here shown that when the Berry phase acquired by the scalar electron encircling the vortex line involves quantized Dirac monopole we have paraxial (non-paraxial) beam when the vortex line is parallel (orthogonal) to the wavefront propagation direction. Non-paraxial beams incorporate spin-orbit interaction. When the vortex line is tilted with respect to the propagation direction the Berry phase involves non-quantized monopole. The temporal variation of the direction of the tilted vortices is studied here taking into account the renormalization group flow of the monopole charge and it is predicted that this gives rise to spin Hall effect.Comment: Accepted for publication in Proceedings of Royal Society

Inertial spin Hall effect in noncommutative space

In the present paper the study of inertial spin current(that appears in an accelerated frame of reference) is extended to Non-Commutative (NC) space. The $\theta$-dependence, ($\theta$ being the NC parameter), of the inertial spin current is derived explicitly. We have provided yet another way of experimentally measuring $\theta$. Our bound on $\theta$ matches with previous results. In Hamiltonian framework, the Dirac Hamiltonian in an accelerating frame is computed in the low energy regime by exploiting the Foldy-Wouthuysen scheme. The NC $\theta$-effect appears from the replacement of normal products and commutators by Moyal *-products and *-commutators. In particular, the commutator between the external magnetic vector potential and the potential induced by acceleration becomes non-trivial. Expressions for $\theta$-corrected inertial spin current and conductivity are derived. The $\theta$ bound is obtained from the out of plane spin polarization, which is experimentally observable.Comment: 11 pages, no figures, Accepted in Phys. Lett.