Professor Ramanathan, Ravishankar

PhD National University of Singapore
Assistant Professor

Tel: (+852) 2859 2350
Fax: (+852) 2559 8447
Email: ravi@cs.hku.hk
Research Group Homepage: https://qift.weebly.com/

Dr. Ramanathan's main research interests are in Quantum Cryptography, specifically Randomness Amplification, Expansion and Key Distribution, Device-Independent Applications of Quantum Theory and Foundations of Quantum Mechanics. He has 32 refereed publications in these areas, including 10 papers in Physical Review Letters and 3 in Nature Communications. He received his B.Eng. degree from the Nanyang Technological University in 2004 and received his MSc and PhD in Physics at the National University of Singapore in 2008 and 2013. Before joining HKU, he spent four years as a Research Fellow at The National Quantum Information Centre at The University of Gdansk and two years as a Postdoctoral Researcher at Universite Libre de Bruxelles and University of Oxford.

Research Interests

Quantum Information Theory, Quantum Cryptography, Device-Independent Quantum Information Processing, Foundations of Quantum Mechanics

Selected Publications

• F. G. S. L. Brandao, R. Ramanathan, A. Grudka, K. Horodecki, M. Horodecki, P. Horodecki, T. Szarek, H. Wojewodka. Realistic noise-tolerant randomness amplification using finite number of devices. Nature Communications 7, 11345 (2016).
• P. Horodecki and R. Ramanathan. *The relativistic causality versus no-signaling paradigm for multi-party correlations*. Nature Communications 10, 1701 (2019).
• R. Ramanathan, D. Goyeneche, S. Muhammad, P. Mironowicz, M. Grunfeld, M. Bourennane and P. Horodecki. Steering is an essential feature of non-locality in quantum theory, Nature Communications 9, 4244 (2018).
• R. Ramanathan, J. Tuziemski, M. Horodecki and P. Horodecki. No Quantum Realization of Extremal No-Signaling Boxes, Physical Review Letters 117, 050401 (2016).
• R. Ramanathan and P. Horodecki. Necessary and Sufficient Condition for State-Independent Contextual Measurement Scenarios, Physical Review Letters 112, 040404 (2014).
• R. Ramanathan, F. Brandao, K. Horodecki, M. Horodecki, P. Horodecki, H. Wojewodka. *Randomness amplification against no-signaling adversaries using two devices*. Physical Review Letters117, 230501 (2016).
• R. Ramanathan, A. Soeda, P. Kurzynski and D. Kaszlikowski. *Generalized monogamy of contextual inequalities from the no-disturbance principle*. Physical Review Letters 109, 050404 (2012).
• R. Ramanathan, M. Rosicka, K. Horodecki, S. Pironio, M. Horodecki, P. Horodecki. *Gadget structures in proofs of the Kochen-Specker theorem*. arXiv: 1807.00113 (2018).
• R. Ramanathan, A. Kay, G. Murta, P. Horodecki. *Characterising the Performance of XOR Games and the Shannon Capacity of Graphs*. Physical Review Letters 113, 240401 (2014).
• R. Ramanathan and P. Horodecki. *Strong monogamies of no-signaling violations for bipartite correlation Bell inequalities. *Physical Review Letters 113, 210403 (2014).
• P. Kurzynski, R. Ramanathan and D. Kaszlikowski. *Entropic test of quantum contextuality.* Physical Review Letters 109, 020404 (2012).
• A. Kay, D. Kaszlikowski and R. Ramanathan. *Optimal cloning and singlet monogamy*. Physical Review Letters 103, 050501 (2009).
• H. Wojewodka, F. G. S. L. Brandao, A. Grudka, M. Horodecki, K. Horodecki, P. Horodecki, M. Pawlowski, R. Ramanathan, M. Stankiewicz. *Amplifying the randomness of weak sources correlated with devices.* IEEE Transactions on Information Theory, vol. 63, no. 11, pp. 7592-7611 (2017).
• R. Ramanathan, M. Horodecki, S. Pironio, K. Horodecki, P. Horodecki. *Generic randomness amplification schemes using Hardy paradoxes. *arXiv: 1810.11648 (2018).