Nanophotonic Beam Splitter Based on Quantum Dots with Förster Coupling

This paper describes the design of a quantum beam splitter that transforms the state of a spatial photonic qubit in two modes due to the exchange of energy between the modes and quantum dots (QDs). By controlling the interaction time, it is possible to obtain the required superposition of the basic single-photon states of the qubit at the output of the device. In addition, the beam splitter allows the generation of entangled two-photon NOON states. Using the Förster effect to control the energy exchange between QDs makes it possible to increase the intermodal distance and suppress unwanted direct interaction of the modes. As an example, a beam splitter based on a two-dimensional photonic crystal (PC) with temperature and structural frequency tuning is considered.