Ultracold Rydberg gases and plasmas
(with T. Pohl, C. Ates and J.M. Rost)
Recently, it has become possible to cool atomic or molecular gases to ultralow
temperatures in the nano-Kelvin range. Due to these advances in experimental
techniques, a wealth of new information has become available. It is fair to say
that with the possibilities to reach atomic Bose-Einstein condensates, arrange
atoms in optical lattices, etc, a whole new branch of atomic physics has
become accessible to experiment. In this project, which is
partially funded by the 'Schwerpunktprogramm Wechselwirkung in ultrakalten
Atom- und Molekülgasen', we are in particular concerned with the
physics of ultracold Rydberg gases and plasmas.
In this field, first experiments have
been made in the last years which found interesting effects, such as the
evolution of the gas into a cold neutral plasma, recombination of the
plasma into Rydberg atoms, modified (as compared to room temperature)
two-body collision dynamics, interaction-induced blockade effects, and more.
Recently, we have predicted that it
should be possible to observe Coulomb crystallization in an unconfined and
expanding neutral plasma by laser-cooling [3].
[1] Ionization and Recombination Dynamics of an Expanding Ultracold
Rydberg Gas; T. Pohl, T. Pattard and J.M. Rost, in Interactions in Ultracold
Gases: From Atoms to Molecules, eds. M. Weidemüller and C. Zimmermann
(Wiley-VCH, 2003) 399
[2] Plasma formation from ultracold Rydberg gases; T. Pohl, T. Pattard
and J.M. Rost, Phys. Rev. A 68 (2003) 010703(R)
[Abstract]
[3] Coulomb crystallization in expanding laser-cooled neutral plasmas; T. Pohl,
T. Pattard and J.M. Rost, Phys. Rev. Lett. 92 (2004) 155003
[Abstract]
[4] On the possibility of `correlation cooling' of ultracold neutral plasmas;
T. Pohl, T. Pattard and J.M. Rost, J. Phys. B 37 (2004) L183
[Abstract]
[5] Existence and stability of cold Rydberg gases and plasmas;
T. Pattard, T. Pohl and J.M. Rost, Few-Body Systems 34 (2004) 181
[Abstract]
[6] Kinetic modelling and molecular dynamics simulation of ultracold
neutral plasmas including ionic correlations;
T. Pohl, T. Pattard and J.M. Rost, Phys. Rev. A 70 (2005) 033416
[Abstract]
[7] Influence of electron-ion collisions on Coulomb crystallization
of ultracold neutral plasmas; T. Pohl, T. Pattard and J.M. Rost,
J. Phys. B 38 (2005) S343
[Abstract]
In connection with this project, I have also
co-organized an International Workshop Rydberg Physics from April 19 to May 14 2004
and
served as a guest editor for a Special Issue on Rydberg Physics in J. Phys. B, Vol. 38, Nr. 2, Jan. 28 2005
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last change: 02/10/05