A Photon Turnstile Dynamically Regulated by One Atom
Barak Dayan,1
A. S. Parkins,1*
Takao Aoki,1
E. P. Ostby,2
K. J. Vahala,2
H. J. Kimble1
Beyond traditional nonlinear optics with large numbers of atoms and photons, qualitatively new phenomena arise in a quantum regime of strong interactions between single atoms and photons. By using a microscopic optical resonator, we achieved such interactions and demonstrated a robust, efficient mechanism for the regulated transport of photons one by one. With critical coupling of the input light, a single atom within the resonator dynamically controls the cavity output conditioned on the photon number at the input, thereby functioning as a photon turnstile. We verified the transformation from a Poissonian to a sub-Poissonian photon stream by photon counting measurements of the input and output fields. The results have applications in quantum information science, including for controlled interactions of single light quanta and for scalable quantum processing on atom chips.
1 Norman Bridge Laboratory of Physics, 12-33, California Institute of Technology, Pasadena, CA 91125, USA.
2 T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA.
* Present address: Department of Physics, University of Auckland, Auckland, New Zealand.
Present address: PRESTO, Japan Science and Technology Agency, Saitama, Japan.
To whom correspondence should be addressed. E-mail: hjkimble{at}caltech.edu
