Chao Yang Lu, Photonic Quantum Computational Advantage

Abstract

The main challenge for scaling up photonic quantum technologies is the lack of perfect quantum light sources. We have pushed the parametric down-conversion to its physical limit and produce two-photon source with simultaneously a collection efficiency of 97% and an indistinguishability of 96% between independent photons. Using a single quantum dot in microcavities, we have produced on-demand single photons with high purity , near-unity indistinguishability, and high extraction efficiency—all combined in a single device compatibly and simultaneously. Based on the high-performance quantum light sources, we have implemented boson sampling—which is an intermediate model of quantum computing, a strong candidate for demonstrating quantum computational advantage and refuting Extended Church Turing Thesis—with up to 76 photon clicks after a 100-mode interferometer. The photonic quantum computer, Jiuzhang, yields an output state space dimension of 10^30 and a sampling rate that is 10^14 faster using the state-of-the-art simulation strategy on supercomputers.


About CFCS Quantum Day
CFCS Quantum Day, organized by Center on Frontiers of Computing Studies (CFCS), Peking University, is a one-day seminar focusing on pioneering works on supremacy, quantum simulation, and applications with near-term quantum computing hardware. Given continued uncertainty surrounding the future of COVID-19 and worldwide travel precautions, CFCS Quantum Day was held online on May 12th, 2021.