The scaling of optical quantum technologies requires efficient, on-demand sources of highly indistinguishable single photons. Semiconductor quantum dots inserted into photonic structures are ultrabright single-photon sources, yet the indistinguishability is limited by charge noise. Parametric downconversion sources provide highly indistinguishable photons but are operated at very low brightness to maintain high single-photon purity. To date, no technology has provided a bright source generating near-unity indistinguishability and pure single photons. Here, we report such devices made of quantum dots in electrically controlled cavities. Application of an electrical bias on the deterministically fabricated structures is shown to strongly reduce charge noise. Under resonant excitation, an indistinguishability of 0.9956 ± 0.0045 is demonstrated with g(2)(0) = 0.0028 ± 0.0012. The photon extraction of 65% and measured brightness of 0.154 ± 0.015 make this source 20 times brighter than any source of equal quality. This new generation of sources opens the way to new levels of complexity and scalability in optical quantum technologies.
At a glance
- Photonic quantum technologies. Nature Photon. 3, 687–695 (2009). , &
- Photonic quantum simulators. Nature Phys. 8, 285–291 (2012). &
- Unconditional room-temperature quantum memory. Nature Phys. 7, 794–798 (2011). , , , &
- How good must single photon sources and detectors be for efficient linear optical quantum computation? Phys. Rev. Lett. 100, 060502 (2008). , &
- Single-photon sources and detectors. Rev. Sci. Instrum. 82, 071101 (2011). , , &
- A scheme for efficient quantum computation with linear optics. Nature 409, 46–52 (2001). , &
- Linear optical quantum computing with photonic qubits. Rev. Mod. Phys. 79, 135–174 (2007). et al.
- Photonic boson sampling in a tunable circuit. Science 339, 794–798 (2013). et al.
- Boson sampling on a photonic chip. Science 339, 798–801 (2013). et al.
- Experimental boson sampling. Nature Photon. 7, 540–544 (2013). et al.
- Experimental validation of photonic boson sampling. Nature Photon. 8, 615–620 (2014). et al.
- Multiphoton entanglement and interferometry. Rev. Mod. Phys. 84, 777–838 (2012). et al.
- Experimental generation of single photons via active multiplexing. Phys. Rev. A 83, 043814 (2011). , , , &
- Full analysis of multi-photon pair effects in spontaneous parametric down conversion based photonic quantum information processing. New J. Phys. 17, 043030 (2015). , &
- Three-photon energy–time entanglement. Nature Phys. 9, 19–22 (2013). et al.
- Nonlinear interaction between single photons. Phys. Rev. Lett. 113, 173601 (2014). et al.
- Triggered single photons from a quantum dot. Phys. Rev. Lett. 86, 1502–1505 (2001). , , , &
- A quantum dot single-photon turnstile device. Science 290, 2282–2285 (2000). et al.
- Efficient out-coupling of high-purity single photons from a coherent quantum dot in a photonic-crystal cavity. Phys. Rev. B 90, 155303 (2014). et al.
- Bright solid-state sources of indistinguishable single photons. Nature Commun. 4, 1425 (2013). et al.
- A highly efficient single-photon source based on a quantum dot in a photonic nanowire. Nature Photon. 4, 174–177 (2010). et al.
- Bright single-photon sources in bottom-up tailored nanowires. Nature Commun. 3, 737 (2012). et al.
- Charge noise and spin noise in a semiconductor quantum device. Nature Phys. 9, 570–575 (2013). et al.
- On-demand semiconductor single-photon source with near-unity indistinguishability. Nature Nanotech. 8, 213–217 (2013). et al.
- Deterministic and robust generation of single photons from a single quantum dot with 99.5% indistinguishability using adiabatic rapid passage. Nano Lett. 14, 6515–6519 (2014). et al.
- Controlled light–matter coupling for a single quantum dot embedded in a pillar microcavity using far-field optical lithography. Phys. Rev. Lett. 101, 267404 (2008). et al.
- Deterministic and electrically tunable bright single-photon source. Nature Commun. 5, 3240 (2014). et al.
- Measurement of subpicosecond time intervals between two photons by interference. Phys. Rev. Lett. 59, 2044–2046 (1987). , &
- Indistinguishable photons from a single-photon device. Nature 419, 594–597 (2002). , , , &
- Quantum-dot single-photon sources: prospects for applications in linear optics quantum-information processing. Phys. Rev. A 69, 032305 (2004). , &
- Coherent control of a solid-state quantum bit with few-photon pulses. Preprint at http://arxiv.org/abs/1512.04725 (2015). et al.
- Highly indistinguishable photons from deterministic quantum-dot microlenses utilizing three-dimensional in situ electron-beam lithography. Nature Commun. 6, 7662 (2015). et al.
- Effects of frequency correlation in linear optical entangling gates operated with independent photons. Phys. Rev. A 76, 043825 (2007).
- Understanding photonic quantum-logic gates: the road to fault tolerance. Preprint at http://arxiv.org/abs/0808.0794 (2008). et al.
- Parametric downconversion and optical quantum gates: two's company, four's a crowd. J. Mod. Opt. 56, 209–214 (2009). et al.
- Generalized multi-photon quantum interference. Phys. Rev. X 5, 041015 (2014). et al.
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