title: Spontaneous two-photon emission from a single quantum dot.
abstract: Spontaneous two-photon emission from a solid-state single quantum emitter is observed. We investigated photoluminescence from the neutral biexciton in a single semiconductor quantum dot coupled with a high Q photonic crystal nanocavity. When the cavity is resonant to the half energy of the biexciton, the strong vacuum field in the cavity inspires the biexciton to simultaneously emit two photons into the mode, resulting in clear emission enhancement of the mode. Meanwhile, the suppression of other single photon emission from the biexciton was observed, as the two-photon emission process becomes faster than the others at the resonance.
authors.affiliation: Institute for Nano Quantum Information Electronics, The University of Tokyo, 4-6-1 Komaba, Tokyo 153-8505, Japan. ota@iis.u-tokyo.ac.jp
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Ota
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwamoto
authors.forename: Naoto
authors.initials: N
authors.lastname: Kumagai
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Arakawa