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Johann DANZLWelcome to the really weird world : probing molecular physics with quantum optics

Abstract :

The talk

Coming from the field of quantum optics, the speaker will give an intuitive overview of the utterly strange, yet completely fundamental laws and effects that govern the universe at the quantum scale, and present some of the recent and exciting experimental progress in investigating quantum phenomena using optics

From the website of the Physics Department University of Innsbruck...

Pinning atoms into order
Fundamental physical phenomena demonstrated in Austria for the first time.
In an international first, physicists of the University of Innsbruck, Austria have experimentally observed a quantum phenomenon, where an arbitrarily weak perturbation causes atoms to build an organized structure from an initially unorganized one.

Quantum phase transition
The Innsbruck physicists have observed a "pinning transition" from a superfluid
("Luttinger liquid") to an insulated phase ("Mott-insulator"). In their experiment they showed that for strongly interacting atoms an additional weak lattice potential was sufficient to pin the atoms to fixed positions along the wire ("pinning"). The atoms were cooled down to nearly absolute zero and were in their quantum mechanical ground state. "It is not thermal fluctuations that induce the phase transition," stresses PhD student Elmar Haller, who is also first author of the study, which has been published in the journal Nature. "In fact, the atoms are already correlated due to strong repulsive interaction and only need a small push to align regularly along the optical lattice," explains Haller. When the lattice is removed, the atoms return to a superfluid state.

Selected publications

Pinning quantum phase transition for a Luttinger liquid of strongly interacting bosons
E. Haller, R. Hart, M.J. Mark, J.G. Danzl, L. Reichsöllner, M. Gustavsson, M. Dalmonte, G. Pupillo, H.-C. Nägerl Nature 66, 597 (2010)

An ultracold high-density sample of rovibronic ground-state molecules in an optical lattice
J. G. Danzl, M. J. Mark, E. Haller, M. Gustavsson, R. Hart, J. Aldegunde, J. M. Hutson, H.-C. Nägerl
Nature Physics 6, 265 (2010),

Realization of an Excited, Strongly Correlated Quantum Gas Phase
E. Haller, M. Gustavsson, M. J. Mark, J. G. Danzl, R. Hart, G. Pupillo, H. -C. Nägerl
Science 325, 1224 (2009)

Scientific focus :

Cette équipe dont fait partie Johann Danzl étudie des atomes ultra-froids qui ont généré un nouvel état exotique de la matière, où les atomes s'alignent en une structure unidimensionnelle, créant une phase stable «à N-corps» avec de nouveaux états quantiques. Publiés dans la revue Science en 2010

Valentin Nagerl