Abhishek Sadhu, a visiting Ph.D student from RRI Bangalore working under the co-supervision Dr. Siddhartha Das presented a poster at the 26th Conference on Quantum Information Processing (QIP 2023) hosted by the Quantum Group of Ghent University, Belgium from 4 – 10 February.
Abhishek Sadhu visited the Quantum Information Theory group at ICFO, Barcelona, led by Prof. Antonio Acín for scientific discussions from 11 to 18 February and gave a seminar. In both these places he presented their research work on Testing of quantum nonlocal correlations under constrained free-will and imperfect detectors.
Research work as explained by the authors: In this work, we deal with relaxation of two central assumptions in the standard locally realistic hidden variable (LRHV) inequalities: free will in choosing of measurement settings and presence of perfect detectors at the measurement devices. Violation of LRHV inequalities by quantum correlations imply that given correlations are quantum nonlocal. However, in an adversarial situation, there could be a hidden variable introducing bias in the selection of measurement settings but observers with no access to hidden variable could be unaware of the bias. Whereas in practice, detectors don’t have perfect efficiency. A main focus of this paper is introduction of the framework where given a quantum state with nonlocal behaviour under constrained free will, we can determine the threshold values of detector parameters (detector inefficiency and dark counts) such that the detectors are robust enough to certify nonlocality. We also introduce a new class of LRHV inequalities with constrained free will and discuss their implications in testing of quantum nonlocal correlations.
Full paper: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.012212