Entanglement in states of a composite (quantum) system -- consisting of far apart subsystems -- is considered to be the most important ingredient for achieving efficient information processing tasks in the quantum world. Unfortunately, maintaining entanglement among the subsystems is a challenging task as quantum systems are quite fragile to the interactions with their environments. As a result, witnessing entanglement in states of a given composite system is of fundamental importance before using the states for any information processing task. Unfortunately, any such entanglement witnessing scheme is state-dependent. On the other hand, for any experimentalist, it is always desirable to have a universal entanglement witnessing scheme which can detect entanglement in a reasonably large class of states of the system -- if not all the states of the system. In this talk I will briefly touch upon our recent efforts in the direction of universal witnessing of entanglement in specific bi-partite systems.
Prof. Sibasish Ghosh completed his Ph.D. in the Physics and Applied Mathematics Unit (PAMU) of ISI-Kolkata and then spent six months (during middle of the year 2001 to the beginning of 2002) at the Univ. of California, Los Angeles (Electrical Engineering Dept.) as a Visiting Researcher. He worked for about one year in PAMU as an NBHM post-doctoral fellow, before joining (in March, 2003) The Institute of Mathematical Sciences (IMSc), Chennai as a post-doc in the Theoretical Physics group. Thereafter, he joined (in April, 2004) as a post-doc in the Computer Science department of the Univ. of York, United Kingdom in the group of Prof. Samuel Braunstein. He joined IMSc in July 2006 as a faculty in the Theoretical Physics group where he is currently a professor. His research interests include foundations of quantum mechanics, quantum information theory, open quantum systems, quantum thermodynamics, and quantum optics.