%0 Book Section %1 statphys23_1141 %A Grimm, R. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K bose condensation einstein fermions feshbach invited resonance statphys23 topic-1 ultracold %T Ultracold Fermi gases %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=1141 %X Quantum-degenerate gases at nanokelvin temperatures can be realized with bosonic and fermionic atoms. Since the first observations of Bose-Einstein condensation in atomic gases in 1995, ultracold gases have opened up a great wealth of research opportunities on quantum matter, cutting across many disciplines of physics. In the last few years, dramatic progress has been achieved in experiments with fermionic quantum gases. The first degenerate Fermi gas was already realized in 1999, but it took until 2002/03 that the first observations of strongly interacting Fermi gases and molecular Bose-Einstein condensation stimulated a rapid development, leading to the observations of many-body pairing, superfluidity and many other exciting phenomena in ultracold Fermi gases.\\ In my talk, I will first present a general overview of research on ultracold fermions. I will then focus on experiments on strongly interacting Fermi gases of lithium-6 atoms in the BEC-BCS crossover. The possibility to experimentally explore the crossover results from the tunability of the two-body interaction near a so-called Feshbach resonance. An external magnetic field controls the scattering length and determines whether bosonic molecules are formed from pairs of fermionic atoms (positive scattering length) or whether pairing follows BCS-type behavior (negative scattering length). For diverging scattering length we can realize a quantum gas in the unitarity limit, which shows universal properties. We explore the intriguing many-body physics in the crossover by radio-frequency spectroscopy and by studies of collective excitations.\\ New avenues of research will become possible in mixtures of different fermionic species, e.g. fermionic pairing of particles with different masses and new regimes of superfluidity. I will present results from our laboratory on the first creation of a fermionic mixture of lithium-6 and potassium-40 and on the exploration of its interaction properties.

@incollection{statphys23_1141, abstract = {Quantum-degenerate gases at nanokelvin temperatures can be realized with bosonic and fermionic atoms. Since the first observations of Bose-Einstein condensation in atomic gases in 1995, ultracold gases have opened up a great wealth of research opportunities on quantum matter, cutting across many disciplines of physics. In the last few years, dramatic progress has been achieved in experiments with fermionic quantum gases. The first degenerate Fermi gas was already realized in 1999, but it took until 2002/03 that the first observations of strongly interacting Fermi gases and molecular Bose-Einstein condensation stimulated a rapid development, leading to the observations of many-body pairing, superfluidity and many other exciting phenomena in ultracold Fermi gases.\\ In my talk, I will first present a general overview of research on ultracold fermions. I will then focus on experiments on strongly interacting Fermi gases of lithium-6 atoms in the BEC-BCS crossover. The possibility to experimentally explore the crossover results from the tunability of the two-body interaction near a so-called Feshbach resonance. An external magnetic field controls the scattering length and determines whether bosonic molecules are formed from pairs of fermionic atoms (positive scattering length) or whether pairing follows BCS-type behavior (negative scattering length). For diverging scattering length we can realize a quantum gas in the unitarity limit, which shows universal properties. We explore the intriguing many-body physics in the crossover by radio-frequency spectroscopy and by studies of collective excitations.\\ New avenues of research will become possible in mixtures of different fermionic species, e.g. fermionic pairing of particles with different masses and new regimes of superfluidity. I will present results from our laboratory on the first creation of a fermionic mixture of lithium-6 and potassium-40 and on the exploration of its interaction properties.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Grimm, R.}, biburl = {https://www.bibsonomy.org/bibtex/2815737acac20f464069a4dd90dbc2b86/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {6f3660ffad8b718cb59348839ce27943}, intrahash = {815737acac20f464069a4dd90dbc2b86}, keywords = {bose condensation einstein fermions feshbach invited resonance statphys23 topic-1 ultracold}, month = {9-13 July}, timestamp = {2007-06-20T10:16:40.000+0200}, title = {Ultracold Fermi gases}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=1141}, year = 2007 }