Quantum interferences and gates with emitter-based coherent photon sources
Ilse Maillette de Buy Wenniger, Stephen C. Wein, D. Fioretto, Sarah E. Thomas, C. Antón, Aristide Lemaître, Isabelle Sagnes, Abdelmounaïm Harouri, Nadia Belabas, Niccolò Somaschi, Paul Hilaire, Jean Sénellart, P. Senellart · Optica Quantum · 2024
Quantum emitters such as quantum dots, defects in diamond or in silicon have emerged as efficient single-photon sources that are progressively exploited in quantum technologies. In 2019, it was shown that the emitted single-photon states often include coherence with the vacuum component. Here we investigate how such photon-number coherence alters quantum interference experiments that are routinely implemented both for characterizing or exploiting the generated photons. We show that it strongly modifies intensity correlation measurements in a Hong–Ou–Mandel experiment and leads to errors in indistinguishability estimations. It also results in additional entanglement when performing partial measurements. We illustrate the impact on quantum protocols by evidencing modifications in heralding efficiency and fidelity of two-qubit gates.