title: Experimental protocol for high-fidelity heralded photon-to-atom quantum state transfer.
abstract: A quantum network combines the benefits of quantum systems regarding secure information transmission and calculational speed-up by employing quantum coherence and entanglement to store, transmit and process information. A promising platform for implementing such a network are atom-based quantum memories and processors, interconnected by photonic quantum channels. A crucial building block in this scenario is the conversion of quantum states between single photons and single atoms through controlled emission and absorption. Here we present an experimental protocol for photon-to-atom quantum state conversion, whereby the polarization state of an absorbed photon is mapped onto the spin state of a single absorbing atom with >95% fidelity, while successful conversion is heralded by a single emitted photon. Heralded high-fidelity conversion without affecting the converted state is a main experimental challenge, in order to make the transferred information reliably available for further operations. We record >80 s(-1) successful state transfer events out of 18,000 s(-1) repetitions.
authors.affiliation: Universität des Saarlandes, Experimentalphysik, Campus E2 6, 66123 Saarbrücken, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kurz
authors.affiliation: Universität des Saarlandes, Experimentalphysik, Campus E2 6, 66123 Saarbrücken, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schug
authors.affiliation: Universität des Saarlandes, Experimentalphysik, Campus E2 6, 66123 Saarbrücken, Germany.
authors.forename: Pascal
authors.initials: P
authors.lastname: Eich
authors.affiliation: Universität des Saarlandes, Experimentalphysik, Campus E2 6, 66123 Saarbrücken, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Huwer
authors.affiliation: Universität des Saarlandes, Experimentalphysik, Campus E2 6, 66123 Saarbrücken, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Müller
authors.affiliation: Universität des Saarlandes, Experimentalphysik, Campus E2 6, 66123 Saarbrücken, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Eschner