Cavity quantum electrodynamics for photon mediated transfer of quantum states

An enhanced approach for transferring quantum state between quantum nodes is proposed wherein photons serve as the information carrier. Each node consists of a Rubidium ((87)Rb) atom trapped inside a two-mode optical cavity. The approach is based on cavity quantum electrodynamics (QED) wherein a system of lasers is applied on the atom in order to generate photon through Raman transition. Logic states '0' and '1' are represented by two subspaces of the hyperfine energy levels with magnetic sub-levels of (87)Rb atom. A static magnetic field is applied upon the atoms so that the hyperfine states of (87)Rb atom are split into the magnetic sub-levels (due to Zeeman effect). Depending on the logic state of the transmit node, a right-or left-circularly polarized photon with designated frequency is produced through a cavity assisted Raman process. When the photon is received at the receive node via an optical fiber, the logic state of the transmit node is restored (through a cavity QED process) into the receive node. A desirable feature of the approach is that, during the transmission of logic state, the transmit node itself should not significantly change its quantum state; this is successfully validated through simulations. (C) 2011 American Institute of Physics. [doi:10.1063/1.3596522]