Engineering Photon-Photon Interactions
Deterministic photon-photon interactions are a long-standing goal in quantum optical science. In our experiments, we use an ensemble of atoms inside of a high finesse optical cavity to mediate effective interactions between photons. We show that this interaction can be transistor-like, where one photon blocks hundreds of photons , or operate as a (partly) non-destructive detector, detecting photons and preserving them some of the time . In a separate experiment, we show that a single photon imparts a phase shift of pi/3 on a weak coherent state traveling in another mode . These experiments demonstrate increasing control over photons, which, with moderate technical improvements, will enable deterministic photonic quantum logic.
 W. Chen, K. M. Beck, R. Bücker, M. Gullans, M. D. Lukin, H. Tanji-Suzuki, V. Vuletić. All-Optical Switch and Transistor Gated by One Stored Photon. Science 341, 768-770 (2013)
 M. Hosseini, K. M. Beck, Y. Duan, W. Chen, V. Vuletić. Partially Nondestructive Continuous Detection of Individual Traveling Optical Photons. arXiv:1511.00559 [quant-ph] (to appear in Physical Review Letters)
 K. M. Beck, M. Hosseini, Y. Duan, V. Vuletić. Large conditional single-photon cross-phase modulation. arXiv:1512.02166 [quant-ph]