Shreekantha Sil

Magneto-transport in a mesoscopic ring with Rashba and Dresselhaus spin-orbit interactions

Electronic transport in a one-dimensional mesoscopic ring threaded by a magnetic flux is studied in the presence of Rashba and Dresselhaus spin-orbit interactions. A completely analytical technique within a tight-binding formalism unveils the spin-split bands in the presence of the spin-orbit interactions and leads to a method of determining the strength of the Dresselhaus interaction. In addition to this, the persistent currents for ordered and disordered rings have been investigated numerically. It is observed that the presence of the spin-orbit interaction, in general, leads to an enhanced amplitude of the persistent current. Numerical results corroborate the respective analytical findings.

Metal-Insulator Transition in an Aperiodic Ladder Network : An Exact Result

We prove that a tight-binding ladder network composed of atomic sites with on-site potentials distributed according to the quasiperiodic Aubry model can exhibit a metal-insulator transition at multiple values of the Fermi energy. For specific values of the first and second neighbor electron hopping, the result is obtained exactly. With a more general model, we numerically calculate the two-terminal conductance. The numerical results corroborate the analytical findings.

Ladder network as a mesoscopic switch: An exact result

We investigate the possibilities of a tight-binding ladder network as a mesoscopic switching device. Several cases have been discussed in which any one or both arms of the ladder can assume random, ordered, or quasiperiodic distribution of atomic potentials. We show that, for a special choice of the Hamiltonian parameters, it is possible to prove exactly the existence of mobility edges in such a system, which plays a central role in the switching action. We also present numerical results for the two-terminal conductance of a general model of a quasiperiodically grown ladder, which support the general features of the electron states in such a network. The analysis might be helpful in fabricating mesoscopic or DNA switching devices.

Anisotropic ferromagnetism in carbon-doped zinc oxide from first-principles studies

A density functional theory study of substitutional carbon impurities in ZnO has been performed, using both the generalized gradient approximation (GGA) and a hybrid functional (HSE06) as exchange-correlation functional. It is found that the non-spinpolarized C

Ground and excited states of a bound polaron in a purely two-dimensional quantum well

_\mathrm{Zn}

Flux-induced semiconducting behavior of a quantum network

impurity is under almost all conditions thermodynamically more stable than the C

A proposal for the measurement of Rashba and Dresselhaus spin–orbit interaction strengths in a single sample

_\mathrm{O}

MULTI-DIMENSIONAL FRÖHLICH BIPOLARON AND DIMENSIONAL SCALING

impurity which has a magnetic moment of

Interplay of magnetic field and geometry in magneto-transport of mesoscopic loops with Rashba and Dresselhaus spin-orbit interactions

2\mu_{\mathrm{B}}

Effect of anisotropy on small magnetic clusters

, with the exception of very O-poor and C-rich conditions. This explains the experimental difficulties in sample preparation in order to realize