Spin Pumping and Measurement of Spin Currents in Optical Superlattices.
We report on the experimental implementation of a spin pump with ultracold bosonic atoms in an optical superlattice. In the limit of isolated double wells, it represents a 1D dynamical version of the quantum spin Hall effect. Starting from an antiferromagnetically ordered spin chain, we periodically vary the underlying spin-dependent Hamiltonian and observe a spin current without charge transport. We demonstrate a novel detection method to measure spin currents in optical lattices via superexchange oscillations emerging after a projection onto static double wells. Furthermore, we directly verify spin transport through in situ measurements of the spins' center-of-mass displacement.
Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstrasse 4, D-80799 München, Germany.|Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
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Schweizer
Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstrasse 4, D-80799 München, Germany.|Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
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Lohse
Dipartimento di Fisica "E. R. Caianiello", Università degli Studi di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy.|SPIN-CNR Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano, Salerno, Italy.
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Citro
Fakultät für Physik, Ludwig-Maximilians-Universität, Schellingstrasse 4, D-80799 München, Germany.|Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
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Bloch