Controllable Photonic Time-Bin Qubits from a Quantum Dot

Abstract

Photonic time-bin qubits are well suited to transmission via optical fibers and waveguide circuits. The states take the form 1 ffiffiffiffi ffi ð2Þ p ðαj0i þ e iϕ βj1iÞ, with j0i and j1i 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-holecharged 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 wavelengthdivision multiplexing at the single-photon level.

Gigahertz-Clocked Teleportation of Time-Bin Qubits with a Quantum Dot in the Telecommunication C Band

“…QDs, on the other hand, natively produce polarization-encoded single photons and entangled photons via the biexciton cascade. To overcome this incompatibility, schemes based on weak pulsed excitation have been developed to implement timebin-encoded single photons [36] and entangled photon pairs [37][38][39][40] directly from quantum dots. Direct timebin-encoded entanglement generation from quantum dots has the advantage that larger FSSs are acceptable [37] but this scheme cannot produce true on-demand entangled pairs without the addition of a metastable state [37,38] and is technically demanding due to the need for phase control between the early and late photons, which can only be achieved with resonant two-photon excitation [39,40].…”

Correlations between optical properties and Voronoi-cell area of quantum dots

“…To connect a QD to an atomic memory based on rubidium, the QD should emit photons matched both in emission energy and bandwidth to the memory 27 . The emission energy can be matched by using GaAs QDs embedded in AlGaAs 28,29 ; bandwidth matching can be achieved by using a Raman-scheme [30][31][32][33] .…”

Photon Phase Shift at the Few-Photon Level and Optical Switching by a Quantum Dot in a Microcavity

“…As the sample is nominally undoped, we use a weak non-resonant pulsed laser to inject a charge with random spin into the QD. [26]. Both positive and negative trions are created in this way, although only one is resonant with the cavity and observed here (see Suplemental Material for further detail [31]).…”