In our classical world, copying is an easy task: you can copy a string in your favorite text editor when coding; you can make a backup of your files locally or on cloud; you can take notes photos or even videos when you attend a talk (like this one). However, things are very different in the quantum region.

In quantum information, the no-cloning theorem claims that it is impossible create an identical copy of an arbitrary unknown quantum state. It is one of the most interesting yet most profound theorems in quantum information, and it has many implications in various subfields in quantum mechanics.

In this talk, I will first introduce the basics of quantum information, including pure states and unitary/isometry evolutions. Then I will provide a proof of the no-cloning theorem. After that, I will talk about several implications of the no-cloning theorem, including secret sharing, quantum teleportation and information disturbance.

The only prerequisite for this talk is a strong foundation in linear algebra. No background knowledge in quantum information is needed. Speaker(s): Cupjin Huang (University of Michigan)