Phonon scattering inhibits simultaneous near-unity efficiency and indistinguishability in semiconductor single-photon sources

Jake Iles-Smith, Dara P. S. McCutcheon, Ahsan Nazir, Jesper Mørk

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Semiconductor quantum dots (QDs) have recently emerged as a leading platform to generate highly indistinguishable photons efficiently, and this work addresses the timely question of how good these solid-state sources can ultimately be. We establish the crucial role of lattice relaxation in these systems in giving rise to trade-offs between indistinguishability and efficiency. We analyse the two source architectures most commonly employed: a QD embedded in a waveguide and a QD coupled to an optical cavity. For waveguides, we demonstrate that the broadband Purcell effect results in a simple inverse relationship, in which indistinguishability and efficiency cannot be simultaneously increased. For cavities, the frequency selectivity of the Purcell enhancement results in a more subtle trade-off, in which indistinguishability and efficiency can be increased simultaneously, although not arbitrarily, which limits a source with near-unity indistinguishability (> 99%) to an efficiency of approximately 96% for realistic parameters.
Original languageEnglish
JournalNature Photonics
Issue number8
Pages (from-to)521-+
Publication statusPublished - 2017


  • Semiconductor Devices and Integrated Circuits
  • Waveguides
  • Production Engineering
  • Atomic and Molecular Physics
  • Quantum Theory
  • High Energy Physics
  • Social Sciences
  • Economic and social effects
  • Efficiency
  • Particle beams
  • Photons
  • Quantum theory
  • Frequency selectivity
  • Indistinguishability
  • Inverse relationship
  • Lattice relaxation
  • Optical cavities
  • Purcell effect
  • Single-photon source
  • Solid-state sources
  • Semiconductor quantum dots

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