QUROPE Quantum Information Processing and Communication in Europe

W. Chen, K.M. Beck, R. Bücker, M. Gullans, M.D. Lukin, H. Tanji-Suzuki and V. Vuletić.
Science 341, 768-770 (2013).

Control of light at the single-photon level is a central goal in quantum photonics. In their work Chen and
colleagues have realised an optical transistor. Coupling is realised via a Quantum Electrodynamics (QED)
architecture with an ensemble of four-level atoms inside a cavity. Absorption of photons by
Electromagnetically Induced Transparency (EIT) modifies the transmission of the cavity, realising an
interface between optical modes controlled by one photon.