Publications (15)
Precision Measurements of Collective Oscillations in the BEC-BCS Crossover
A. Altmeyer, S. Riedl, C. Kohstall +6
We report on precision measurements of the frequency of the radial compression mode in a strongly interacting, optically trapped Fermi gas of Li-6 atoms. Our results allow for a te…
Crossover from a molecular Bose-Einstein condensate to a degenerate Fermi gas
M. Bartenstein, A. Altmeyer, S. Riedl +4
We demonstrate a reversible conversion of a Li2 molecular Bose-Einstein condensate to a degenerate Fermi gas of atoms by adiabatically crossing a Feshbach resonance. By optical in…
Evidence for Efimov quantum states in an ultracold gas of cesium atoms
T. Kraemer, M. Mark, P. Waldburger +8
Systems of three interacting particles are notorious for their complex physical behavior. A landmark theoretical result in few-body quantum physics is Efimov's prediction of a univ…
Determination of atomic scattering lengths from measurements of molecular binding energies near Feshbach resonances
A. D. Lange, K. Pilch, A. Prantner +5
We present an analytic model to calculate the atomic scattering length near a Feshbach resonance from data on the molecular binding energy. Our approach considers finite-range squa…
First-order phase transition in atom-molecule quantum degenerate mixtures with coherent three-body recombination
G. A. Bougas, A. Vardi, H. R. Sadeghpour +2
We map the phase diagram of a two-mode atom-molecule Bose-Einstein condensate with Fano-Feshbach and coherent three-body recombination (cTBR) terms. The standard second order phase…
Observation of Feshbach-like resonances in collisions between ultracold molecules
C. Chin, T. Kraemer, M. Mark +4
We observe magnetically tuned collision resonances for ultracold Cs2 molecules stored in a CO2-laser trap. By magnetically levitating the molecules against gravity, we precisely me…
Pure Gas of Optically Trapped Molecules Created from Fermionic Atoms
S. Jochim, M. Bartenstein, A. Altmeyer +4
We report on the production of a pure sample of up to 3x10^5 optically trapped molecules from a Fermi gas of 6Li atoms. The dimers are formed by three-body recombination near a Fes…
Precise determination of Li cold collision parameters by radio-frequency spectroscopy on weakly bound molecules
M. Bartenstein, A. Altmeyer, S. Riedl +9
We employ radio-frequency spectroscopy on weakly bound Li molecules to precisely determine the molecular binding energies and the energy splittings between molecular states…
`Stückelberg interferometry' with ultracold molecules
M. Mark, T. Kraemer, P. Waldburger +4
We report on the realization of a time-domain `Stückelberg interferometer', which is based on the internal state structure of ultracold Feshbach molecules. Two subsequent passages…
Exploring the BEC-BCS Crossover with an Ultracold Gas of Li Atoms
M. Bartenstein, A. Altmeyer, S. Riedl +5
We present an overview of our recent measurements on the crossover from a Bose-Einstein condensate of molecules to a Bardeen-Cooper-Schrieffer superfluid. The experiments are perfo…
Efficient creation of molecules from a cesium Bose-Einstein condensate
M. Mark, T. Kraemer, J. Herbig +3
We report a new scheme to create weakly bound Cs molecules from an atomic Bose-Einstein condensate. The method is based on switching the magnetic field to a narrow Feshbach res…
Spectroscopy of Ultracold, Trapped Cesium Feshbach Molecules
M. Mark, F. Ferlaino, S. Knoop +5
We explore the rich internal structure of Cs_2 Feshbach molecules. Pure ultracold molecular samples are prepared in a CO_2-laser trap, and a multitude of weakly bound states is pop…
Experimental Evidence for Efimov Quantum States
H. -C. Naegerl, T. Kraemer, M. Mark +8
Three interacting particles form a system which is well known for its complex physical behavior. A landmark theoretical result in few-body quantum physics is Efimov's prediction of…
Observation of the Pairing Gap in a Strongly Interacting Fermi Gas
C. Chin, M. Bartenstein A. Altmeyer, S. Riedl +3
We study fermionic pairing in an ultracold two-component gas of Li atoms by observing an energy gap in the radio-frequency excitation spectra. With control of the two-body inte…
Collective excitations of a degenerate gas at the BEC-BCS crossover
M. Bartenstein, A. Altmeyer, S. Riedl +4
We study collective excitation modes of a fermionic gas of Li atoms in the BEC-BCS crossover regime. While measurements of the axial compression mode in the cigar-shaped trap c…