title: Ultrafast all-optical coherent control of single silicon vacancy colour centres in diamond.
abstract: Complete control of the state of a quantum bit (qubit) is a fundamental requirement for any quantum information processing (QIP) system. In this context, all-optical control techniques offer the advantage of a well-localized and potentially ultrafast manipulation of individual qubits in multi-qubit systems. Recently, the negatively charged silicon vacancy centre (SiV-) in diamond has emerged as a novel promising system for QIP due to its superior spectral properties and advantageous electronic structure, offering an optically accessible Λ-type level system with large orbital splittings. Here, we report on all-optical resonant as well as Raman-based coherent control of a single SiV-using ultrafast pulses as short as 1 ps, significantly faster than the centre's phonon-limited ground state coherence time of about 40 ns. These measurements prove the accessibility of a complete set of single-qubit operations relying solely on optical fields and pave the way for high-speed QIP applications using SiV-centres.
authors.affiliation: Fachrichtung 7.2 (Experimentalphysik), Universität des Saarlandes, Campus E2.6, 66123 Saarbrücken, Germany.
authors.forename: Jonas Nils
authors.initials: JN
authors.lastname: Becker
authors.affiliation: Fachrichtung 7.2 (Experimentalphysik), Universität des Saarlandes, Campus E2.6, 66123 Saarbrücken, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Görlitz
authors.affiliation: Fachrichtung 7.2 (Experimentalphysik), Universität des Saarlandes, Campus E2.6, 66123 Saarbrücken, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Arend
authors.affiliation: Global Innovation Centre, Element Six Limited, Global Innovation Centre, Fermi Avenue, Harwell Oxford, Didcot, Oxfordshire OX11 0QR, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Markham
authors.affiliation: Fachrichtung 7.2 (Experimentalphysik), Universität des Saarlandes, Campus E2.6, 66123 Saarbrücken, Germany.
authors.forename: Christoph
authors.identifier: 0000-0003-4645-6882
authors.initials: C
authors.lastname: Becher