Physics Colloquium

A Topological Quantum Computer, Inside a Gauge Theory, Inside a Quantum Computer

Topological quantum matter lies at the intersection of many-body quantum physics, quantum information theory, and high-energy physics. One of its remarkable lessons is that gauge theories, familiar from the Standard Model, can emerge from quantum entanglement. However, it has been difficult to realize and control the most exotic cases, which host non-Abelian anyons: quasiparticles that remember how they move around one another, and whose motion can be used to process quantum information.

In this colloquium, I will describe how quantum processors can create such gauge theories from scratch. Surprisingly, wavefunction collapse from quantum measurement is a key tool for creating such states. Most recently, this has led to the 54-qubit realization of a gauge theory based on S3, the smallest non-Abelian group, where we demonstrated the fundamental building blocks of a universal topological quantum computer using its anyonic quasiparticles. More broadly, these approaches give a concrete handle on the typically abstract physics of non-Abelian topological order, opening new directions in the study of decoherence, error correction, and fault-tolerant quantum computation.

Join via Zoom:
https://caltech.zoom.us/j/84497014003
Meeting ID: 844 9701 4003

The colloquium is held in Feynman Lecture Hall, 201 E. Bridge.