I work on Quantum Information and Computation. My research interests include quantum communication, detection and quantification of quantum correlations, interface of many-body physics with quantum, information science etc.

**Quantum Communication:** In classical computers, one has to transfer
information from one part of the computer to another. This is also true for quantum computer circuits.
However, in this case, the transferred information can be classical or quantum. Moreover, the channel carrying
the information also follows quantum rules. Such quantum channels also have several important quantum communication applications,
independent of their use in quantum computers. Developing the
theory of quantum channels is a major aim of my research (PRL **91**, 117901 (2003); PRL **93**, 170503 (2004);
PRL **93**, 210501 (2004); PRA **81**, 012308 (2010)).

BCS in Capacity

I am interested in channels realizable with
currently available technology. For example, channels carrying modes of electromagnetic fields or channels carrying
massive particles. (While the former has an impressive body of research, the same is not true for latter. However, we had worked in this direction
in PRL **95 **, 260503 (2005).) This
research is intimately related with fields like quantum optics, Bose-Einstein condensation, etc.

I also work on ** the security of quantum cryptography ** (PRA **68**, 032309 (2003); PRA **80**, 012311 (2009)) in the multipartite scenario.

** Quantification of quantum correlations ** is also one of my major research interests. Towards this aim, we have introduced two entanglement measures based on two physical phenomena, no cloning and no deleting (PRA **70**, 052326 (2004)). Recently, we have introduced a genuine multipartite entanglement measure in PRA **81**, 012308 (2010). Moreover, we also have worked on quantification of quantum correlation from a thermodynamic point of view (PRL **90**, 100402 (2003); PRA **71**, 062307 (2005); arXiv:1108.5168; arXiv:1109.4318; arXiv:1112.1856).

Relation between two quantum correlation measures of two classes of three-qubit states

I also work at the ** interface of
quantum many-body physics with quantum computation**.
I have been working on this subject for the last few years. I have co-authored a review on this theme,
emphasising on ultracold gases (``Ultracold atomic gases in optical lattices: Mimicking condensed matter physics and beyond'',
Advances in Physics **56**, 243-379 (2007) (cond-mat/0606771, Citations:626)). Recent works in this direction include Phys. Rev. Lett. **101**, 187202 (2008); Phys. Rev. A **84**, 042334 (2011); Europhys. Lett. ** 95**, 50008 (2011) ; J. Phys. A: Math. Theor. **44**, 465302 (2011). A figure of the last paper has been selected as a cover page of an issue of J. Phys. A).

Benford's law, detecting phase transition