Controlling fluorescence of two level systems for heterogeneous quantum networks

By harnessing the advantages of different quantum technologies, heterogeneous quantum networks are promising candidates for enhanced timing, sensing, communication, and information processing. In typical quantum networks, identical photons, emitted by their parent qubits, interfere on a beam splitter to create heralded entanglement between network nodes. However, creating entanglement between heterogeneous qubits is complicated by the interference of the qubits' distinguishable photons. We show the fluorescence spectrum of a two-level atomic system can be controlled by modulating an excitation laser, and the fluorescence of the two-level system can be tuned to more closely match that of other systems. The matched spectra can then be used in standard heralded photon interference schemes to create entanglement between different remote qubits.  Our results show this scheme's prospects as a generic entanglement bus between different types of qubits in a quantum network. Distribution A: cleared for public release. Case AFRL-2021-0182