Nonlinear optics with ultrastrong light-matter coupling
When atoms and photons are ultrastrongly coupled, higher-order processes, which do not conserve the number of excitations in the system, become possible. In this work, we show how this can be used to realize analogs of a large number of well-known nonlinear-optics phenomena, e.g., three- and four-wave mixing, Raman scattering, the Kerr effect, and much more. In contrast to most conventional implementations of nonlinear optics, these analogs can reach unit efficiency, only use a minimal number of photons (they do not require any strong external drive), and do not require more than two atomic levels. We estimate that many of these analogs are ready to be implemented in circuit-QED experiments.
Deterministic quantum nonlinear optics with single atoms and virtual photons
Anton Frisk Kockum, Adam Miranowicz, Vincenzo Macrì, Salvatore Savasta, and Franco Nori
arXiv:1701.05038