## ECE Colloquium: Kallol Roy (UNIST) – “Quantum Algorithmic Engineering With Photonic Integrated Circuits”

2015.09.18- Date
- ( ~ )
- Location

- Speaker

Abstract:

Integrated quantum photonics show monolithic waveg- uide chips to be a promising platform for realising the next generation of quantum optical circuits. This work proposes the implementation of quantum pageR- ank algorithm on a photonic waveguide lattice. Our contributions are as follows: Continuous-time quantum stochastic walk(QSW)-an alternate paradigm of quantum computing, is a hybrid quantum walk that incorporates both unitary and non-unitary effects. We propose the use of QSW which necessitates the hopping of the quantum crawler on a directed graph, for the quantum pageRank problem. We propose the implementation of quantum pageRank on a photonic waveguide lattice, where we allow the density matrix to evolve according to the Lindblad-Kossakowski master equation, the diagonal of which gives the quantum pageRank. We have also shown the use of the metric of positional Kolmogorov Complexity as an efficient tool for determining whether or not the quantum channel has been compromised. We positionally encode multi-photon decoy pulses within the stream of single photon pulses. This positional encoding is chosen in such a way as to have low Kolmogorov complexity. The PNS attack on the multi-photon decoy pulses causes a dip in the ratio of the transmittance of the decoy pulses to the signal pulses in the conventional analysis.

Speaker Bio:

Dr. Kallol Roy completed his BS from Department of Elecrical Engineering at Indian Institute of Technology Kanpur. After his BS he has worked for some time as a Research Assistant in the theoretical Sciences Division at SN Bose National Center For Basic Science, Kolkata, India. He then joined the Electrical Communication Engineering Department at Indian Institute of Science Bangalore for his Masters and Ph.D programme and completed it on 2014. His research topic during his Ph.D is Quantum Algorithms and Quantum Cryptography. After his Ph.D, he has joined Department of Mathematics, Indian Institute of Science Bangalore, as a Postdoctoral Researcher. From August 19, 2015 he has joined Probabilistic Artificial Intelligence Lab of Prof. Jaesik Choi, UNIST, as a Postdoctoral Researcher. His current areas of interest are Deep Machine Learning, Big Data Analytics, Scalable Inference Engine Design, Topological Data Analysis. He is the recipent of APS-IUSSTF Physics Student Visitation Award, 2012 Microsoft Travel Award, Sterlite Best Paper Award at Photonics 2010, IIT Guwahati, MHRD Scholarship, Government of India 2007, Jawaharlal Nehru Scholarship Steel Authority of India Limited, 2000.