RSS icon
Twitter icon
Facebook icon
Vimeo icon
YouTube icon

Measuring topological invariants in few-level quantum system

April 10, 2015 - 12:00pm
Seiji Sugawa
JQI, NIST/University of Maryland

Understanding topological nature of physical system is one of the most important topics in modern physics. In condense matter, non-trivial topological phase is characterized by non-zero Chern number. In particle physics, solitons and monopole solutions of non-Abelian gauge theories are characterized by their topological charges. Here, we prepared few-level quantum system by dressing hyperfine ground states of 87Rb with radio frequency and microwave fields, and measured the first Chern number in parameter space by observing non-adiabatic response due to local Berry curvature. The non-zero value of the topological invariants can be understood as resulting from monopole sources.

2136 PSC
College Park, MD 20742

Subscribe to A Quantum Bit 

Quantum physics began with revolutionary discoveries in the early twentieth century and continues to be central in today’s physics research. Learn about quantum physics, bit by bit. From definitions to the latest research, this is your portal. Subscribe to receive regular emails from the quantum world. Previous Issues...

Sign Up Now

Sign up to receive A Quantum Bit in your email!

 Have an idea for A Quantum Bit? Submit your suggestions to