Chitres Guria successfully defends thesis, “Measuring the geometry and topology of non-Hermitian systems”

On February 20, Chitres Guria successfully defended the thesis, “Measuring the geometry and topology of non-Hermitian systems” (advisor: Jack Harris).

Guria explained, “My thesis is a study of Newtonian mechanics of a simple, humble but ubiquitous system of coupled classical harmonic oscillators, and whose parameters like spring constant, mass, damping etc. can be tuned, both statically (like DC) and in real time. One may wonder why we are studying something that is a part of undergrad classical mechanics and the complimentary homework problems? What is still left to be discovered?”

Guria continued, “Turns out there were still new insights yet to be unveiled, and some of them can be of practical utility. Our work theoretically and experimentally demonstrates remarkable geometric and topological structures that are present in every collection of oscillators: both in its static properties such as their eigenvalues and normal modes (like eigenvectors) or its real time evolution. These studies are done in the domain of non-Hermitian physics, and the experiments utilized the Yale-invented and more precisely Jack Harris lab-invented Membrane-in-the-middle optomechanical system.”

Guria added, “Sir Isaac Newton’s Principia Mathematica (1687) turns 340, next year. It won’t be a big stretch to regard this book as a holy book for physicists – almost Biblical!”

Thesis abstract: In this thesis, we study qualitatively new non-Hermitian phenomena that occur when the parameters of coupled harmonic oscillators are tuned (like mass, spring constant, and damping), while monitoring their motion. We consider both forms of tuning: static and real time. These phenomena are demonstrated experimentally using the membrane-in the-middle (MIM) optomechanical system. 

Thesis committee: Jack Harris (advisor), Nicholas Read, Peter Rakich, Konrad Lehnert, and Kater Murch (University of California, Berkeley)