Physics Colloquium, "Testing Quantumness in the NISQ Era"

Presented By: Umesh Vazirani, University of California, Berkeley, Dept. of Computer Science Host: Rahul Nandkishore Colloquium Date: October 18, 2023 Abstract: We are well into the NISQ era of Noisy Intermediate Scale Quantum Computers. Four years on from Google's ‘quantum supremacy’ experiment, we have a deeper understanding of the nature of that experiment, the computing power of NISQ and novel techniques for benchmarking such computers and characterizing their error models. At a foundational level, quantum supremacy provides a test of quantum mechanics in a new regime. I will also describe how concepts from cryptography have provided novel and counter-intuitive ways of probing quantum systems, and the prospects they hold for the next generation of quantum computers taking on the quantum supremacy challenge. Bio: Umesh Vazirani is Strauch Distinguished Professor of Computer Science at UC Berkeley, Director of the Berkeley Quantum Computing Center (BQIC) and Research Director for Quantum Computing at the Simons Institute. His research has focussed on the foundations of Quantum Complexity Theory, Quantum Algorithms, Quantum Hamiltonian Complexity and Interactive classical testing of quantum devices. Vazirani is co-winner of the Fulkerson Prize for the ARV graph partitioning algorithm, a member of the National Academy of Sciences, and co-author of two books: An Introduction to Computational Learning Theory, and Algorithms.