Thorsten Schumm
One-dimensional Bose gases: from surface probing to high-order correlations
We realize one-dimensional quasi condensates in the weakly interacting regime based on highly anisotropic magnetic micro traps on an atom chip. The enormous sensitivity of ultracold atoms to feeble distortions of the trapping potential allows us to probe local magnetic fields and hence reconstruct the current density inside a metal conductor [1]. We find surprising long-range order in the electron transport of a room temperature gold wire [2].Using dressed adiabatic radio frequency potentials [3] we dynamically split the one-dimensional quasi condensates and gain access to the coherence properties in matter wave interferometry [4]. Spatial phase correlations are investigated by a quantum noise analysis of the emerging interference contrast [5]. De-coherence dynamics are investigated after a dynamic splitting process, preparing the system in a highly non-equilibrium state of the system [6]. Current work focuses on the characterization of the thermodynamic equilibrium state of two coupled one-dimensional condensates.
To probe higher order correlations, we implement a fluorescence detector that reaches single atom detection together with high spatial resolution [7]. This new scheme allows us to measure two-particle correlation functions of expanding Bose gases across the BEC phase transition for three- and one-dimensional samples.
[1] S. Wildermuth, S. Hofferberth, I. Lesanovsky, E. Haller, M. Andersson, S. Groth, I. Bar-Joseph, P.Krüger, J. Schmiedmayer, Bose-Einstein condensates: Microscopic Magnetic Field Imaging, Nature 435, 440 (2005)
[2] S. Aigner, L. Della Pietra, Y. Japha, O. Entin-Wohlman, T. David, R.Salem, R. Folman, J. Schmiedmayer, Long-Range Order in Electronic Transport through Disordered Metal Films, Science 319, 1226 (2008)
[3] I. Lesanovsky, T. Schumm, S. Hofferberth, L. M. Andersson, P. Krüger, J. Schmiedmayer, Adiabatic radio frequency potentials for the coherent manipulation of matter waves, Phys. Rev. A 73, 033619 (2006)
[4] T. Schumm, S. Hofferberth, L. M. Anderson, S. Wildermuth, S. Groth, I. Bar-Joeseph, J. Schmiedmayer and P. Krüger, Matter-wave interferometry in a double well on a atom chip, Nature Physics 1 57 (2005)
[5] S. Hofferberth, I. Lesanovsky, T. Schumm, A. Imambekov, V. Gritsev, E. Demler , J. Schmiedmayer, Probing quantum and thermal noise in an interacting many-body system, Nature Phys. 4, 489-495 (2008)
[6] S. Hofferberth, I. Lesanovsky, B. Fischer, T. Schumm, and J. Schmiedmayer, Non-equilibrium coherence dynamics in one-dimensional Bose gases, Nature 449, 324-327 (2007)
[7] R. Bücker, A. Perrin, S. Manz, T. Betz, Ch. Koller, T. Plisson, J. Rottmann, T. Schumm, J. Schmiedmayer, Single-atom-sensitive fluorescence imaging of ultracold quantum gases, arXiv:0907.0674 (2009)
