BEC

Bose-Einstein Condensates in Optical Lattices

While the physics of the previous century is mainly characterized by great advances in the understanding of the properties of one-particle systems, recent experimental developments have put the effects of interactions at the top of the current research agenda. The most fascinating of these experimental achievements was the realization of Bose-Einstein Condensation (BEC) of ultra-cold atoms in optical lattices (OL) and the creation of “atom chips” which are suggested as potential building blocks for quantum information processing while at the same time they allow for novel, concrete applications of quantum mechanics such as atom interferometers and atom lasers. The precise tailoring and manipulation of OLs on the other hand has allowed us to investigate complex solid state phenomena, such as the Mott-Insulator to superfluid transition, the Josephson effect, the atom blockade phenomenon in quantum- dot-like potentials, Anderson localization [2,6], and Bose-Glass transitions.

In fact, it is envisioned that the emerging field of atomtronics, i.e. the atom analogue of electronic materials, devices, and circuits, will be able to provide much more powerful devices with respect to the solid-state ones. A major advantage of BEC based devices, lies in the extraordinary degree of precision and control that is available, regarding not only the confining potential, but also the strength of the interatomic interaction, their preparation and the measurement of the atomic cloud.

Based on these facts, we have recently proposed a quantum pumping/stirring device of BEC which produces an adiabatic DC atomic current by a periodic AC variation of the depth and the tunneling between adjacent wells of an optical lattice [1]. The feasibility of this concept has been demonstrated and it was be pointed out how such a device can be utilized in order to probe the inter-atomic interactions. The induced current is extremely accurate and would open the way to various applications, either as a metrological standard, or as a component of a new type of quantum information/processing device.

Finally, interacting bosonic systems – having a well defined classical limit – provide an excellent playground where fundamental issues related to decoherence [3], and the advancement of classical, semiclassical [4], and statistical methods can be addressed.

References

1. Inelastic chaotic scattering on a Bose-Einstein condensate
   Stefan Hunn, Moritz Hiller, Andreas Buchleitner, Doron Cohen, Tsampikos Kottos
   J. Phys. B 45 085302 (2012)
2. Matter-wave scattering on a BEC in a double-well potential
   S. Hunn, M. Hiller, A. Buchleitner, D. Cohen and T. Kottos
   Eur. Phys. J. D 10, 1140 (2011)
3. Semiclassical analysis of quantum dynamics in the bosonic Josephson junction
   Maya Chuchem, Katrina Smith-Mannschott, Moritz Hiller, Tsampikos Kottos, Amichay Vardi, Doron Cohen
   Phys. Rev. A 82, 053617 (2010)
4. Avalanches of Bose-Einstein condensates in leaking optical lattices
   G. S. Ng, H. Hennig, R. Fleischmann, T. Kottos, and T. Geisel
   New J. Phys. 11, 073045 (2009)
5. Occupation Statistics of a BEC for a Driven Landau-Zener Crossing
   Katrina Smith-Mannschott, Maya Chuchem, Moritz Hiller, Tsampikos Kottos, and Doron Cohen
   Phys. Rev. Lett. 102, 230401 (2009)
6. Wavepacket Dynamics in Energy Space of a chaotic trimeric Bose-Hubbard system
   Moritz Hiller, Tsampikos Kottos and Theo Geisel
   Phys. Rev. A 79, 023621 (2009)
7. Controlled quantum stirring of Bose-Einstein condensates
   Moritz Hiller, Tsampikos Kottos and Doron Cohen
   Phys. Rev. A 78, 013602 (2008).
8. Control of atomic currents using a quantum stirring device
   Moritz Hiller, Tsampikos Kottos and Doron Cohen
   Europhys. Lett. 82, 40006 (2008).
9. Wavepacket dynamics of the nonlinear Harper model
   Gim Seng Ng and Tsampikos Kottos
   Phys. Rev. B 75, 205120 (2007).
10. Engineering fidelity echos in Bose-Hubbard Hamiltonians
    Joshua D. Bodyfelt, Moritz Hiller, and Tsampikos Kottos
    Europhys. Lett. 78, 50003 (2007).
11. Complexity in parametric Bose-Hubbard Hamiltonians and structural analysis of eigenstates
    Moritz Hiller, Tsampikos Kottos, and T. Geisel
    Phys. Rev. A 73, 061604(R) (2006).
12. Bifurcations in resonance widths of an open Bose-Hubbard dimer
    Moritz Hiller, Tsampikos Kottos, and Alexander Ossipov
    Phys. Rev. A 73, 063625 (2006).
13. Current Relaxation in Nonlinear Random Media
    Tsampikos Kottos and Matthias Weiss
    Phys. Rev. Lett. 93, 190604 (2004).