Hannover 2016 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 47: Quantum Information: Quantum Computing and Communication I
Q 47.7: Talk
Thursday, March 3, 2016, 12:30–12:45, e214
Microwave near-field control of 9Be+ qubits in a surface-electrode ion trap — •Martina Wahnschaffe1,2, Henning Hahn1,2, Giorgio Zarantonello1,2, Sebastian Grondkowski2, Timko Dubielzig2, Amado Bautista-Salvador1,2, Matthias Kohnen1,2, and Christian Ospelkaus1,2 — 1QUEST Institute for Experimental Quantum Metrology, PTB, Bundesallee 100, D-38116 Braunschweig — 2Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, D-30167 Hannover
We describe experiments employing microwave near-fields from conductors embedded in a surface-electrode ion trap [1]. Our optimized trap geometry features a single conductor to induce all the required spin-motional couplings typically used in multi-qubit quantum operations [2]. We load 9Be+ ions via two-photon ionization from an ablation plume created by single shots of a pulsed laser. Our experiment operates at 22.3 mT where the |F=2,mF=1> and |F=1,mF=1> states form a first-order field-independent qubit for long coherence times. We demonstrate initialization and control of the qubit. We perform a spatial characterization of the microwave near-field employing a modified Ramsey / echo sequence with a single ion as a local field probe and find good agreement with full-wave numerical simulations. Using the spatial variation of the microwave near-field, we demonstrate motional sideband transitions on our field-independent qubit as a basic prerequisite for entangling multi-qubit quantum logic gates.
[1] C. Ospelkaus et al., Phys. Rev. Lett. 101, 090502 (2008)
[2] M. Carsjens et al., Appl. Phys. B 114, 243 (2014)