Speaker:Â Â Dr. Chitres Guria Title:Â Measuring the geometry and topology of non-Hermitian systems Abstract:Â This talk will discuss many surprises one may encounter when studying a simple, humble but ubiquitous system of coupled classical harmonic oscillators whose parameters can be tuned, both statically and in real time. Such systems are studied under the domain of non-Hermitian physics. I will specifically focus on the interplay between non-Hermiticity and geometric phase. We find that for non-degenerate systems, the Berry phase is a complex number, whose imaginary part represents a geometric loss/gain unique to non-Hermitian systems. We demonstrate these features experimentally in the real time evolution of a lossy two-mode system. Furthermore, we show that geometric gain allows us to demonstrate a novel form of amplification. The topological aspects will be mentioned briefly.