Zobrazeno 1 - 10
of 47
pro vyhledávání: '"Grond, Julian"'
Autor:
Grond, Julian, Streltsov, Alexej I., Lode, Axel U. J., Sakmann, Kaspar, Cederbaum, Lorenz S., Alon, Ofir E.
Publikováno v:
Phys. Rev. A 88, 023606 (2013)
We derive a general linear-response many-body theory capable of computing excitation spectra of trapped interacting bosonic systems, e.g., depleted and fragmented Bose-Einstein condensates (BECs). To obtain the linear-response equations we linearize
Externí odkaz:
http://arxiv.org/abs/1307.1667
Autor:
Bücker, Robert, Berrada, Tarik, van Frank, Sandrine, Schaff, Jean-François, Schumm, Thorsten, Schmiedmayer, Jörg, Jäger, Georg, Grond, Julian, Hohenester, Ulrich
Publikováno v:
J. Phys. B: At. Mol. Opt. Phys. 46 104012 (2013)
We present theoretical and experimental results on high-fidelity transfer of a trapped Bose-Einstein condensate into its first vibrationally excited eigenstate. The excitation is driven by mechanical motion of the trap, along a trajectory obtained fr
Externí odkaz:
http://arxiv.org/abs/1212.4173
Autor:
Bücker, Robert, Hohenester, Ulrich, Berrada, Tarik, van Frank, Sandrine, Perrin, Aurélien, Manz, Stephanie, Betz, Thomas, Grond, Julian, Schumm, Thorsten, Schmiedmayer, Jörg
Publikováno v:
Phys. Rev. A 86, 013638 (2012)
We develop a model for parametric amplification, based on a density matrix approach, which naturally accounts for the peculiarities arising for matter waves: significant depletion and explicit time-dependence of the source state population, long inte
Externí odkaz:
http://arxiv.org/abs/1203.5357
Publikováno v:
Phys. Rev. A 86, 063607 (2012)
Linear response of simple (i.e., condensed) Bose-Einstein condensates is known to lead to the Bogoliubov- de Gennes equations. Here, we derive linear response for fragmented Bose-Einstein condensates, i.e., for the case where the many-body wave funct
Externí odkaz:
http://arxiv.org/abs/1201.0714
Autor:
Alon, Ofir E., Streltsov, Alexej I., Sakmann, Kaspar, Lode, Axel U. J., Grond, Julian, Cederbaum, Lorenz S.
Publikováno v:
Chem. Phys. 401, 2 (2012)
The multiconfigurational time-dependent Hartree method (MCTDH) [Chem. Phys. Lett. {\bf 165}, 73 (1990); J. Chem. Phys. {\bf 97}, 3199 (1992)] is celebrating nowadays entering its third decade of tackling numerically-exactly a broad range of correlate
Externí odkaz:
http://arxiv.org/abs/1109.4429
Autor:
Grond, Julian, Betz, Thomas, Hohenester, Ulrich, Mauser, Norbert J., Schmiedmayer, Joerg, Schumm, Thorsten
Publikováno v:
New J. Phys. 13 065026 (2011)
We analyze the emergence of Shapiro resonances in tunnel-coupled Bose-Einstein condensates, realizing a bosonic Josephson junction. Our analysis is based on an experimentally relevant implementation using magnetic double well potentials on an atomchi
Externí odkaz:
http://arxiv.org/abs/1102.1459
Autor:
Bücker, Robert, Grond, Julian, Manz, Stephanie, Berrada, Tarik, Betz, Thomas, Koller, Christian, Hohenester, Ulrich, Schumm, Thorsten, Perrin, Aurélien, Schmiedmayer, Jörg
Publikováno v:
Nature Physics 7, 608 (2011)
We present highly efficient emission of twin-atom beams into a single transversal mode of a waveguide potential. The source is a one-dimensional degenerate Bose gas in the first radially excited state. We directly measure a suppression of fluctuation
Externí odkaz:
http://arxiv.org/abs/1012.2348
Publikováno v:
Phys. Rev. A 84, 023619 (2011)
We theoretically analyze a Mach-Zehnder interferometer with trapped condensates, and find that it is surprisingly stable against the nonlinearity induced by inter-particle interactions. The phase sensitivity, which we study for number squeezed input
Externí odkaz:
http://arxiv.org/abs/1010.3273
Publikováno v:
New J. Phys. 12, 065036 (2010)
Interferometry with ultracold atoms promises the possibility of ultraprecise and ultrasensitive measurements in many fields of physics, and is the basis of our most precise atomic clocks. Key to a high sensitivity is the possibility to achieve long m
Externí odkaz:
http://arxiv.org/abs/1002.0265
Publikováno v:
Phys. Rev. A 80, 053625 (2009)
We theoretically analyze atom interferometry based on trapped ultracold atoms, and employ optimal control theory in order to optimize number squeezing and condensate trapping. In our simulations, we consider a setup where the confinement potential is
Externí odkaz:
http://arxiv.org/abs/0908.1634