Electronic transport through a driven quantum wire: possible tuning of junction current, circular current and induced local magnetic field.

We propose a new route of getting controlled electron transmission through a molecular wire having a single loop geometry, by irradiating the loop with an arbitrarily polarized light. Along with conventional junction current, a new current called bias driven circular current can be established in the loop under certain conditions depending on the junction configuration. This current, on the other hand, induces a strong magnetic field that can even reach to few tesla. All the physical phenomena can be regulated selectively by adjusting the irradiation parameters. In addition, we put forward another new route of regulating transport behavior by introducing a new path due to the proximity of the contact electrodes for a typical junction configuration. Employing a tight-binding framework, we include the effect of light irradiation within a minimal coupling scheme following the well known Floquet ansatz. Using the wave-guide theory we compute two-terminal transmission probability, and the currents are determined through the Landauer-Büttiker formalism. The present analysis may be utilized to investigate transport phenomena in any other molecular wires as well as tailor-made geometries having simple and/or complex loop sub-structures.