Fully integrated quantum photonic circuit with an electrically driven light source based on carbon nanotubes

The scalable integration of single photon sources, detectors and linear optical elements in a common platform is essential for many applications in quantum cryptography, simulation, and computation. Nanophotonic circuits... [ view full abstract ]

The scalable integration of single photon sources, detectors and linear optical elements in a common platform is essential for many applications in quantum cryptography, simulation, and computation. Nanophotonic circuits combined with on-chip superconducting nanowire provide a suitable solution for the detection side. Integratable and reproducible single photon emitters, however, still have to be developed. Optically excited semiconducting carbon nanotubes (CNTs) can serve as quantum emitters operating in the telecommunication wavelength range. As recently reported, dielectrophoretically deposited CNTs can also be used as waveguide-integrated electrically driven light sources [1] with narrow-line emission profile [2]. The optical properties of such emitters were tuned by pre-sorting of CNT suspensions before the deposition and can be additionally narrowed by photonic circuit design [2]. Here we show that CNTs can act as electroluminescent non-classical emitters [3]. The nanophotonic device (Fig.1) consists of CNT-based emitter in the center (E) and two equidistant detectors (D), embedded within the same photonic integrated circuit. The electrically generated light efficiently couples into and propagates inside the waveguides, and is recorded with integrated traveling-wave single photon detectors (D) at cryogenic conditions. Correlation function recorded in Hanbary-Brown and Twiss-like configuration demonstrates pronounced antibunching (Fig.2), which is a clear signature of non-classical nature of light. Therefore, we realized a fully integrated photonic quantum circuit with purely electrical drive and semiconducting CNT as non-classical source.
[1] S. Khasminskaya, F. Pyatkov et. al., Adv. Mater. 26, 3465–3472 (2014).
[2] F. Pyatkov, V. Fütterling et. al., Nat. Photon. 10, 420-427 (2016).
[3] S. Khasminskaya, F. Pyatkov et. al., Nat. Photon. 10, 727–732 (2016).