Stuttgart 2012 – wissenschaftliches Programm
Q 35.48: Poster
Mittwoch, 14. März 2012, 16:30–19:00, Poster.I+II
Synchronization and coherent transport of atomic qubits for quantum information processing — •Sascha Tichelmann, Malte Schlosser, Moritz Hambach, Felix Schmaltz, and Gerhard Birkl — Institut für Angewandte Physik, Technische Universität Darmstadt, Schlossgartenstraße 7, 64289 Darmstadt, Germany
The coherent control of the internal and external quantum states of ultra-cold neutral atoms represents an important approach towards quantum information processing. We present an experimental implementation of physically independent qubits arranged in a scalable quantum register. Key elements of our approach are two-dimensional registers of optical micro-potentials with pitch in the micrometer regime created by microfabricated lens arrays which inherently provide single-site addressability. This architecture is complemented by the implementation of a scalable quantum shift register that offers precise control of the position and transport of trapped neutral-atom qubits and can serve as a 2D quantum state register to store and sequentially shuffle quantum information in complex architectures. We show the scalability of the transport process by performing the repeated hand-over of atoms from trap to trap on a millisecond timescale and demonstrate the conservation of coherence during transport. We also present an experimental scheme for the cancellation of the differential light shift that is extendable to all alkali elements and arbitrary trapping wavelengths. The resulting “magic-wavelength” behaviour leads to a strong suppression of dephasing and ensures scalability by synchronizing the coherent evolution of qubits at all register sites.