YQI Colloquium - Jack Harris - Yale

Event time: 
Friday, October 15, 2021 - 12:00pm to 1:00pm
YQI Researchers
Hybrid - YQI Seminar Room/Zoom See map
Event description: 
Measuring the eigenvalue topology near higher-order exceptional points: braids & knots are generic features in coupled oscillators
Non-Hermitian systems exhibit a number of surprising features, many of which are still poorly understood. One example is “spectral flow”, which is the evolution of a system’s eigenvalue spectrum when its parameters are varied around a closed path. It is widely appreciated that spectral flow is determined by the manner in which this path encloses the degeneracies known as exceptional points (EPs). However, the general relationship between the path, the EPs, and the spectral flow is less well-known. In this talk I will give a pedagogical introduction to this topic and its relationship to a range of physical systems. I will describe how braids and knots naturally emerge as generic features in eigenvalue spectra, and will present measurements of these features in a cavity optomechanical system.
Colloquium hosted at YQI in person - Join the Zoom link here for livestream