Berlin 2008 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 27: Symposium: Circuit QED
TT 27.5: Talk
Thursday, February 28, 2008, 11:35–12:00, H 0104
Observation of Berry’s Phase in a Superconducting Qubit Embedded in a Cavity — •Peter Leek1, Johannes Fink1, Alexandre Blais2, Romeo Bianchetti1, Martin Goeppl1, Jay Gambetta3,4, David Schuster4, Luigi Frunzio4, Robert Schoelkopf4, and Andreas Wallraff1 — 1Department of Physics, ETH Zürich, Switzerland — 2Département de Physique, Université de Sherbrooke, Québec, Canada — 3Institute for Quantum Computing, University of Waterloo, Canada — 4Departments of Applied Physics and Physics, Yale University, USA
In quantum information science, the phase of a wavefunction plays an important role in encoding information. While most experiments in this field rely on dynamic effects to manipulate this information, an alternative approach is to use geometric phase, which has been argued to have potential fault tolerance [1]. Here we demonstrate the controlled accumulation of a geometric phase, Berry’s phase, in a superconducting qubit, manipulating the qubit geometrically using microwave radiation, and observing the accumulated phase in an interference experiment [2]. This is achieved using the excellent phase coherence and qubit control possible in Circuit QED [3]. We find excellent agreement with Berry’s predictions, and also observe a geometry dependent contribution to dephasing.
J.A. Jones et al., Nature 403, 869 (2000).
[2] P.J. Leek et al., Science, 22 November 2007 (10.1126/science.1149858).
[3] A. Wallraff et al., Nature 431, 162 (2004).