Ouyang Group

Research Focus

In this research group at Sheffield, we focus on the theory and the intersection of quantum error correction and quantum metrology. In particular, we are interested in a diverse range of topics in quantum computing, such as:

1. Quantum error correction
2. Quantum metrology, intersecting with quantum error correction, and also pure quantum metrology in the multiparameter estimation setting
3. Quantum information tasks, such as learning
4. Quantum cryptography: applications of quantum homomorphic encryption with information-theoretic security

We are also proud to be part of the UK QCI3 Hub, contributing on the topic of quantum error correction.

Team

• Postdocs: Heather Leitch, Kaushik Senthoor
• PhD Students: Lewis Bulled, Ellen Brightman (incoming)
• Alumni: Kao-Yueh Kuo (Faculty at Yuan Ze University, Taoyuan, Taiwan)

Yingkai Ouyang is an EPSRC Quantum Technologies Fellow at the University of Sheffield. Previously, Yingkai was a postdoc with Marco Tomamichel, Earl Campbell, and Joseph Fitzsimons. Yingkai graduated with a PhD from the University of Waterloo (in Combinatorics and Optimization) with Debbie Leung, and did a Bachelors in Physics in Caltech. At Caltech, Yingkai did a summer project with John Preskill.

Yingkai's core competency lies in quantum error correction and mathematical optimisation theory. Quantum systems are fragile. To maximise the potential of existing quantum hardware, it is pertinent to optimise their performance subject to practical and realistic constraints. Yingkai's primary speciality within quantum error correction lies in constructing bespoke quantum error correction codes that satisfy prescribed physical constraints. A prominent example of such codes are permutation-invariant quantum codes, which are invariant under any permutation of the underlying qubits. Such quantum codes can be optimised for quantum applications such as quantum sensors, amongst the multitude of quantum technologies.

We like to bring theoretical constructions closer to reality, and so our theory is informed by experimental needs. Yingkai's secondary expertise lies in multiparameter quantum metrology theory, wherein there are strong connections with optimisation theory.

Resources