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Zoom Link: https://zoom.us/j/93797026305?pwd=uhQSPJFd5MN2XjZMwEn4FOSJzMeTFo.1

Abstract: This talk presents a comprehensive journey through computation models, focusing on continuous-time quantum walks and their application to the fundamental problem of sampling. We begin by introducing computational models and showing how quantum systems naturally evolve through continuous-time dynamics. This leads us to continuous-time quantum walks (CTQWs) as a fundamental model of quantum computation on graphs. The core of the talk addresses the important problem of sampling from complex distributions. We analyse CTQW mixing times on structured graphs—specifically, periodic lattices and Cayley graphs and characterise when quantum walks provide speedups over classical random walks in reaching stationary distributions. Importantly, we show how these complex graphs can be physically implemented on superconducting quantum chips via CTQWs. This analysis directly applies to accelerating Markov Chain Monte Carlo methods, a crucial tool in machine learning, statistics, and optimisation.
Finally, we briefly explore quantum query complexity through the set membership problem, demonstrating how quantum superposition enables efficient data querying with fundamental space-query tradeoffs. The talk bridges theoretical foundations with practical applications, showing how quantum approaches can provide genuine advantages for the fundamental task of sampling and beyond.

About the Spekaer: Shyam Dhamparkar is a Postdoctoral Fellow in the Computer Science Department at Chennai Mathematical Institute. He holds a PhD in Physics from the Institute of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen. His research focuses on quantum algorithms, quantum walks, and their computational advantages over classical counterparts. His work spans quantum mixing on periodic lattices, graph embedding on low-dimensional qubit architectures, applications of quantum walks to sampling and thermalisation problems, and data structure problems with quantum queries. He has published in journals and conferences, including ICALP, Physica A, Communications in Theoretical Physics, and IEEE QCNC, bridging the fields of quantum algorithm design and computational complexity. He has delivered invited talks at institutions including UCL, Peking University and the IIIT Hyderabad, and has taught courses in quantum computation and quantum random walks.

We look forward to your active participation.