A wonderful lecture “Quantum Computers: New Opportunities and Challenges”, given by Professor Yu Yang of Nanjing University, was held online on the afternoon of September 29.

In the first part of the lecture, Prof. Yu introduced a major event taking place in 2019 in the area of quantum computing: the quantum computer developed by Google could complete in 200 seconds the tasks that would take top supercomputers 10,000 years, allowing Google to achieve quantum supremacy. The event also intensified the international race for quantum computing and brought multiple challenges to research and development in China.  

Prof. Yu led us to the world of quantum mechanics. He started from the differences between the quantum world and the classical world and talked about three characteristics of the former, namely, the description, the movement and the projective measurement of the system.

Prof. Yu introduced the major topic of quantum information processing and expounded on the scientific results achieved and the application and technological challenges faced in the four main application areas of quantum communication, quantum precision measurement, special-purpose quantum computer, and general-purpose quantum computer.

Taking Shor’s Algorithm and Grover’s Search Algorithm as examples, Prof. Yu demonstrated again the extreme efficiency of quantum computers.

In terms of the operating speed of quantum computers, Prof. Yu explained that quantum computing was based on the superposition of quantum mechanics to allow internal parallelism, thus realizing efficient computing.

In addition, Prof. Yu talked about the current development difficulties in quantum bit manipulation, quantum measurement and control system and two-bit coupling design, as well as challenges of increasing fidelity and decoherence.

From the broader perspective of quantum computing, Professor Yu Yang revealed the development prospect of this area in an approachable way. His lecture not only expanded the students’ horizons and aroused their interest, but also inspired them to continue their study and research with more enthusiasm.