Abstract
Heralded entangling quantum gates are an essential element for the implementation of large-scale optical quantum computation. Yet, the experimental demonstration of genuine heralded entangling gates with free-flying output photons in linear optical system, was hindered by the intrinsically probabilistic source and double-pair emission in parametric down-conversion. Here, by using an on-demand single-photon source based on a semiconductor quantum dot embedded in a micropillar cavity, we demonstrate a heralded controlled-NOT (CNOT) operation between two single photons for the first time. To characterize the performance of the CNOT gate, we estimate its average quantum gate fidelity of . As an application, we generated event-ready Bell states with a fidelity of . Our results are an important step towards the development of photon-photon quantum logic gates.
- Received 28 October 2020
- Accepted 2 March 2021
DOI:https://doi.org/10.1103/PhysRevLett.126.140501
© 2021 American Physical Society