title: Manipulation and coherence of ultra-cold atoms on a superconducting atom chip.
abstract: The coherence of quantum systems is crucial to quantum information processing. Although superconducting qubits can process quantum information at microelectronics rates, it remains a challenge to preserve the coherence and therefore the quantum character of the information in these systems. An alternative is to share the tasks between different quantum platforms, for example, cold atoms storing the quantum information processed by superconducting circuits. Here we characterize the coherence of superposition states of (87)Rb atoms magnetically trapped on a superconducting atom chip. We load atoms into a persistent-current trap engineered next to a coplanar microwave resonator structure, and observe that the coherence of hyperfine ground states is preserved for several seconds. We show that large ensembles of a million of thermal atoms below 350 nK temperature and pure Bose-Einstein condensates with 3.5 × 10(5) atoms can be prepared and manipulated at the superconducting interface. This opens the path towards the rich dynamics of strong collective coupling regimes.
authors.affiliation: 1] CQ Center for Collective Quantum Phenomena and their Applications in LISA+, Physikalisches Institut, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 14, D-72076, Tübingen, Germany [2] [3].
authors.forename: Simon
authors.initials: S
authors.lastname: Bernon
authors.forename: Helge
authors.initials: H
authors.lastname: Hattermann
authors.forename: Daniel
authors.initials: D
authors.lastname: Bothner
authors.forename: Martin
authors.initials: M
authors.lastname: Knufinke
authors.forename: Patrizia
authors.initials: P
authors.lastname: Weiss
authors.forename: Florian
authors.initials: F
authors.lastname: Jessen
authors.forename: Daniel
authors.initials: D
authors.lastname: Cano
authors.forename: Matthias
authors.initials: M
authors.lastname: Kemmler
authors.forename: Reinhold
authors.initials: R
authors.lastname: Kleiner
authors.forename: Dieter
authors.initials: D
authors.lastname: Koelle
authors.forename: József
authors.initials: J
authors.lastname: Fortágh