Damping and Topological Properties of a Coupled Spin-Photon System

Research paper by Michael Harder, Lihui Bai, Paul Hyde, Can-Ming Hu

Indexed on: 15 Feb '17Published on: 15 Feb '17Published in: arXiv - Physics - Materials Science


We experimentally examine the role of damping in a strongly coupled spin-photon system. The presence of both spin and photonic losses results in a non-Hermitian system with a variety of exotic phenomena dictated by the topological structure of the eigenvalue spectra. By controlling both the spin resonance frequency and the spin-photon coupling strength we observe behaviour such as a resonance crossing within the strong coupling regime as well as mode switching when encircling an exceptional point, where the coupled spin-photon eigenvectors coalesce. Furthermore, by adding a second cavity mode we demonstrate the potential to engineer the topological structure in such spin-photon systems. Our work therefore further highlights the role of damping within the strong coupling regime, and demonstrates the potential and great flexibility of spin-photon systems for studies of non-Hermitian physics.