本周四（10月13日）上午11点，光科系邀请南洋理工大学刘爱群教授做线上邀请报告“基于光子芯片的量子计算机”，具体信息如下或见附件，欢迎各位老师及同学积极参加。

Professor Ai-Qun Liu

Director, Quantum Science & Engineering Centre (QSec)

Nanyang Technological University, Singapore 639798

(eaqliu@ntu.edu.sg)

Photonic Chip Brings Quntum Computers One Step Closer

Quantum computers promise to deliver enormous computational power and solve problems that cannot be tackled by ordinary (classical) machines. There are many hardware platforms on which quantum computing can be developed, and it is not yet clear which technology, or combination of technologies, will prove most successful. Today, the leading schemes are based on superconducting electrical circuits or trapped-ion technologies. Another approach, based on photonics, has often been considered impractical because of difficulties in generating the required quantum states, or transformations of such states, on demand. However, this method could turn out to be the dark horse of quantum computing. Today I will give an overview of silicon photonic chip-based quantum computers. In the computing architecture used to implement this quantum sampling algorithm, squeezed states of light are generated and launched into an optical network consisting of several optical paths and beam splitters. The squeezed states mix together when they meet in beam splitters because of a quantum effect called interference. As a result, all the states come out completely scrambled, in a way that depends on the relative lengths of the optical paths, known as their relative phases. Reprogramming these phases alters the type of scrambling. After scrambling, the number of photons in each output of this quantum circuit is counted using highly sensitive detectors. The quantum computer is implemented their photonic circuit on a silicon chip technology that is compatible with the fabrication processes used by the semiconductor industry.

Professor Ai-Qun Liu (A. Q. Liu) received his PhD degree from National University of Singapore (NUS) and is a Professor in the School of Electrical and Electronic Engineering at Nanyang Technological University (NTU). Currently, he is also the Director at the Quantum Science and Engineering (QSec) at NTU, His research interests include quantum computers, quantum communication and quantum enginnering and fabrcation. He has published over 200 peer-reviewed journal papers, 3 books and also received multiple prestigious awards and honours including Singapore Prestigious Engineering Achievement Award. He was elevated to a Fellow of Singapore Engineering Academic, and also Fellow of SPIE, Fellow of OSQ and Fellow of RCS.