Ultrakalte Atome in periodisch modulierten Potenzialen: Ein quantenmechanisches Metamaterial zur Erforschung von Systemen fernab vom Gleichgewicht sowie zur Simulation relativistischer Effekte
Zusammenfassung der Projektergebnisse
We demonstrated that, by using periodic modulations and the technique of Fourier synthesis of optical potentials, a plethora of new effects characteristic to quantum nonequilibrium and relativistic physics can be explored. With a dilute atomic rubidium Bose-Einstein condensate in a variable optical lattice potential, the phenomenon of relativistic Veselago lensing was experimentally demonstrated for the first time in matter waves. In other work with the cold atom system, a topologically protected edge state between two regions of different topological order was spatially resolved. In the course of the project, we also realized, with ultracold rubidium atoms in a timemodulated optical lattice potential, a quantum rocking ratchet. Both the existence and the possibility to control quantum Floquet resonances could be experimentally demonstrated. The presence of these resonances in the transport characteristics of ac-driven quantum ratchets, as well as a universal bifurcation scenario they undergo upon increase of the modulation amplitude, were predicted by the Augsburg team in a theoretical paper. We found very good agreement of our experimental results with the predictions of the theoretical model. Tuneable band structures of optical potentials and the possibility to create a quasi-cone dispersion with a controllable gap, by bringing low energy bands into avoiding crossing, potentially allows to realize another paradigmatic model, the quantum Rabi Hamiltonian. We demonstrated (so far in theory) that, by changing the quasi-momentum of the atoms, the system can be tuned into the deep strong coupling regime, an issue hardly attainable with other systems.
Projektbezogene Publikationen (Auswahl)
- Vesleago lensing with ultracold atoms in an optical lattice, Nature Comm. 5, 3327 (2014)
M. Leder, C. Grossert, and M. Weitz
(Siehe online unter https://doi.org/10.1038/ncomms4327) - Experimental control of transport resonances in a coherent quantum rocking ratchet, Nature Comm. 7, 10440 (2016)
C. Grossert, M. Leder, S. Denisov, P. Hänggi, and M. Weitz
(Siehe online unter https://doi.org/10.1038/ncomms10440) - Phase dependent loading of Bloch bands and quantum simulation of relativistic wave equation predictions with ultracold atoms in variably shaped optical lattice potentials, J. Mod. Opt. 63, 1805 (2016)
C. Grossert, M. Leder, and M. Weitz
(Siehe online unter https://doi.org/10.1080/09500340.2015.1137370) - Real-space imaging of a topological protected edge state with ultracold atoms in an amplitudechirped optical lattice, Nature Comm. 7, 13112 (2016)
M. Leder, C. Grossert, L. Sitta, M. Genske, A. Rosch, and M. Weitz
(Siehe online unter https://doi.org/10.1038/ncomms13112) - Asymptotic Floquet states of open quantum systems: The role of interactions, New J. Phys. 19, 083011 (2017)
M. Hartmann, D. Poletti, M. Ivanchenko, S. Denisov, P. Hänggi
(Siehe online unter https://doi.org/10.1088/1367-2630/aa7ceb) - Quantum Rabi model in the Brillouin zone with ultracold atoms, Phys. Rev. A 95, 013827(2017)
S. Felicetti, E. Rico, C. Sabin, T. Ockenfels, J. Koch, M. Leder, C. Grossert, M. Weitz, and E. Solano
(Siehe online unter https://doi.org/10.1103/PhysRevA.95.013827) - Quantum resonant activation, Phys. Rev. E 95, 042104 (2017)
L. Magazzu, P. Hänggi, B. Spagnolo, and D. Valenti
(Siehe online unter https://doi.org/10.1103/PhysRevE.95.042104) - Role of work in matter exchange between finite quantum systems, New J. Phys. 19, 093006 (2017)
E. Jeon, P. Talkner, J. Yi, Y. K. Kim
(Siehe online unter https://doi.org/10.1088/1367-2630/aa8110)
