Colliding photons and instantons in superconducting circuits
This event is part of the Biophysics/Condensed Matter Seminar Series.
Light does not typically scatter light, as witnessed by the linearity of Maxwell's equations. Using linear chains of Josephson junctions, we constructed superconducting circuits, in which microwave photons have well-defined energy and momentum, but their lifetime is finite due to decay into lower energy photons. The inelastic photon-photon interaction originates from quantum phase-slip fluctuations and has no analogs in quantum optics. In fact, the surprisingly high photon decay rate is explained by mapping the system to a Luttinger liquid with impurities. In this talk I will introduce an electrical engineer's view of quantum phase-slips  and overview our recent experimental studies of photon-instanton collisions . TIme permitting, I will discuss the relevance of our results in the contexts of quantum impurity models , quantum thermalization in closed systems, and superconductor-insulator transition in one-dimensional superconductors .
 arXiv:1907.02937 (Nature 2020)  arXiv:2010.02099  arXiv:2010.02630  arXiv:1805.07379 (Nature Physics 2019)