Physical Review A 85, 013823 (2012)
Wang and collaborators show that it is possible to store a single-photon pulse in a two-level atom within a half cavity setup where the decay rate between the atom and the light is controlled by motion of the one mirror in the half cavity.
A dipole-field interaction leading to optical Bloch equations from Heisenberg picture is used; the effects of the half-cavity are encoded in a term accounting for decay into the half-cavity (pulse) mode, decay and noise introduced by the environment are also taken into account. Assumptions include: Markov approximation (long half-life times compared to light's round-trip between atom and mirror), small mirror motion (of the order of a wavelength) leading to neglect amplitude changes in time scales smaller or equal to a round-trip time—but this cannot be assumed in the phases due to the importance of interferences in the sysme—
The probability of the two-level system absorbing a single-photon wave packet is found and a suitable decay function is given that maximizes such probability. Storage is achieved by placing the atom at a node of the half-cavity system. Then, the emission efficiency is calculated and a decay rate is defined which controls the temporal shape of the outgoing single-photon pulse. The authors present simulations for a sampling of time-bin single-photon pulses and their respective control decay-rate leading to high fidelity storage and possible implementations of their protocol.
The article is didactic in its presentation and the topic is quite interesting. I was not familiar with half-cavity schemes and this manuscript presents a nice survey of references in the topic. I hope experiments using their protocol follow soon.
No comments:
Post a Comment