Abstract
Quantum dots (QDs) are an excellent single-photon source that can be combined with a spin quantum memory. Many quantum technologies require increased control over the characteristics of emitted photons. A powerful approach is to trigger coherent Raman photons from QDs with a Λ energy-level system, such as the spin singlet–triplet system in two coupled QDs. The temporal and spectral behavior of single Raman photons can be varied simply by modifying the excitation source. Here, we demonstrate control of the single-photon pulse shape in a solid-state system on a timescale much shorter than the radiative lifetime, in addition to control of the frequency and bandwidth. We achieve a photon pulse width of 80 ps—an order of magnitude shorter than the exciton lifetime. Possible applications include time-bin encoding of quantum information, matching photons from different sources, and efficient single-photon transfer in a quantum network.
Highlights
Quantum dots (QDs) are an excellent single-photon source that can be combined with a spin quantum memory
Previous work has demonstrated that this technique can be used to tune the emitted photons up to ∼0.5 meV in photonic crystal cavities for both a single QD16 and a quantum dot molecule (QDM)[26] and that the photons are highly indistinguishable[27]
Recent results have shown that coherent Rayleigh scattering from QD two-level systems can result in highly coherent emission determined by the properties of the laser, including control of the temporal profile[28]
Summary
Quantum dots (QDs) are an excellent single-photon source that can be combined with a spin quantum memory. Detuned Raman spin-flip emission has the advantages of a large bandwidth, spectral separation between the emitted photon and the laser pulse, and a ground-state spin system for quantum memory. This technique has been used with trapped ions and atoms in optical cavities to control single-photon wavepackets on a timescale of 0.1–1 μs[29,30]. We confirm single-photon emission and achieve Raman photon pulses of 80-ps duration—an order of magnitude shorter than the exciton lifetime
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.