Quantum computers use the laws of quantum physics, such as superposition and entanglement, for processing information. In recent years, significant efforts have been undertaken to build quantum processors with many qubits based on various physical systems, from both academia and industry companies such as Google, IBM, Microsoft, Intel and IonQ. While these systems are approaching the ∼ 50−100 qubits scale and the potential of achieving quantum supremacy, the accumulation of errors in these systems limit the use of them in solving real-life problems. With the recent focus on investigating the use of these devices in the so-called Noisy Intermediate-Scale Quantum era, it is believed that in the long term, universal, large-scale quantum computers must be able to error-correct and perform in a fault-tolerant manner. In this talk, we discuss the principle of quantum computer, the theory of fault-tolerance, and the practical challenges for building universal, large-scale quantum computers.
 

Bei Zeng received the B.Sc. degree in physics and mathematics and M.Sc. degree in physics from Tsinghua University, in 2002 and 2004, respectively.  She received the Ph.D. degree in physics from Massachusetts Institute of Technology (MIT) in 2009. From 2009 to 2010, she was a postdoctoral fellow at the Institute for Quantum Computing (IQC) and the Department of Combinatorics & Optimization, University of Waterloo. In 2010, she joined the Department of Mathematics & Statistics, University of Guelph, as an assistant professor, and promoted to Tenured Associate Professor in 2014 and Professor in 2018. She is a fellow of the Canadian Institute for Advanced Research (CIFAR), an associate faculty of IQC and an adjunct Professor of the Department of Physics & Astronomy at the University of Waterloo, an affiliate faculty of the Perimeter Institute for Theoretical Physics (PI), and a member of the Guelph-Waterloo Physics Institute (GWPI).