Tomorrow Yuxiang will give a more detailed look at his recent research. See below for title and abstract. The zoom link is https://ethz.zoom.us/j/362994444.

Best,

-joe

Title:  
Optimal universal programming of unitary gates

Abstract:

A universal quantum processor is a device that takes as input a (quantum) program, containing an encoding of an arbitrary unitary gate, and a (quantum) data register, on which the encoded gate is applied. While no perfect universal quantum processor can exist, approximate processors have been proposed in the past two decades. A fundamental open question is how the size of the smallest quantum program scales with the approximation error. Here we answer the question, by proving a bound on the size of the program and designing a concrete protocol that attains the bound in the asymptotic limit. Our result is based on a connection between optimal programming and the Heisenberg limit of quantum metrology, and establishes an asymptotic equivalence between the tasks of programming, learning, and estimating unitary gates. 

This talk will be based on https://arxiv.org/abs/2007.10363.