Congratulations to Dr Manik Banik, School of Physics, whose recent work has been accepted for publication in the prestigious journal Physical Review Letters
Distinguishability among different objects is an elementary notion that shapes our worldview and has immense implications in information processing. For instance, states of a classical system, described by points in phase space, are always perfectly distinguishable. While moving to quantum realm, different states can be distinguished exactly if and only if the states are mutually orthogonal. However, mutually orthogonal states of a quantum system involving several spatially separated subsystems may not be perfectly distinguished when operations among different subsystems are limited (popularly known as the paradigm of LOCC). This particular phenomenon known by the name local indistinguishability is a vastly explored research area in quantum information theory. Local indistinguishability can be overcome by access of multiple copies of the given quantum system. In a recent work we analyse multi-copy local indistinguishability of two-qubit orthogonal bases and show that one can assign varying hardness of local indistinguishability to these bases. During the process we address a question asked 20 years back in a seminal work by Charles H. Bennett et al [Phys. Rev. A 59, 1070 (1999)]
Title: Multicopy adaptive local discrimination: Strongest possible two-qubit nonlocal bases
Authors: M. Banik, T. Guha, M. Alimuddin, G. Kar, S. Halder, and S. S. Bhattacharya
Link: Accepted in Physical Review Letters