Abstract:

In this era of miniaturized devices, we have been trying to develop various quantum theories to describe charge transfer, transport, optical and magnetic phenomena within a unified approach. Towards this end, I shall discuss our efforts to understand Negative differential Resistance/Conductance (NDR/NDC) phenomena in molecules and quantum dots, using both voltage-constraint and current-constraint approaches [1-4]. I shall also discuss one electronics work that we have carried out on DNA systems as well as putting magnetic atoms (Cu, Mn etc) within modified DNA helices[5-7]. And towards the end, I shall also touch upon one recent work, which is how to control current through a nanojunction device by use of laser light, where several exotic effects, like PAT (photon assisted tunneling) and CDT (coherent destruction of tunneling) can be realized.

1. S. Lakshmi, S. Dutta and S. K. Pati, J. Phys. Chem. C 112, 14718 (2008) [Feature Article].

2. B. Muralidharan, A. W. Ghosh, S. K. Pati and S. Datta, IEEE Nano Trans. 6, 536 (2007).

3. P. Parida, S. Lakshmi and S. K Pati, J. Phys.: Cond. Matt. 21, 095301 (2009).

4. P. Parida, S. K. Pati and A. Painelli, Phys. Rev. B 83, 165404 (2011).

5. S. S. Mallajosyula and S. K. Pati, Phys. Rev. Lett. 98, 136601 (2007).

6. S. S. Mallajosyula, et. al , Phys. Rev. Lett. 101, 176805 (2008).

7. S. S. Mallajosyula and S. K. Pati, J. Phys. Chem. Lett. 1, 1881 (2010) [Perspective Review]