Controllable photonic time-bin qubits from a quantum dot

©+eiφβ|1©), with |0© and |1© referring to the early and late time bin, respectively. By controlling the phase of a laser driving a spin-flip Raman transition in a single-hole-charged InAs quantum dot, we demonstrate complete control over the phase, φ. We show that this photon generation process can be performed deterministically, with only a moderate loss in coherence. Finally, we encode different qubits in different energies of the Raman scattered light, paving the way for wavelength-division multiplexing at the single-photon level. © 2018 authors. Published by the American Physical Society. Photonic time-bin qubits are well suited to transmission via optical fibers and waveguide circuits. The states take the form 1(2)(α|0