Effective microscopic models for sympathetic cooling of atomic gases

Cooling Atomic Gases With Disorder.

Cold atomic gases have proven capable of emulating a number of fundamental condensed matter phenomena including Bose-Einstein condensation, the Mott transition, Fulde-Ferrell-Larkin-Ovchinnikov pairing, and the quantum Hall effect. Cooling to a low enough temperature to explore magnetism and exotic superconductivity in lattices of fermionic atoms remains a challenge. We propose a method to prod...

Sympathetic cooling with two atomic species in an optical trap.

We simultaneously trap ultracold lithium and cesium atoms in an optical dipole trap formed by the focus of a CO2 laser and study the exchange of thermal energy between the gases. The optically cooled cesium gas efficiently decreases the temperature of the lithium gas through sympathetic cooling. Equilibrium temperatures down to 25 microK have been reached. The measured cross section for thermal...

Spin gases as microscopic models for non-Markovian decoherence

We analyze a microscopic decoherence model in which the total system is described as a spin gas. A spin gas consists of N classically moving particles with additional, interacting quantum degrees of freedom (e.g. spins). For various multipartite entangled probe states, we analyze the decoherence induced by interactions between the probeand environmental spins in such spin gases. We can treat me...

Sympathetic cooling of bosonic and fermionic Lithium gases towards quantum degeneracy

Sympathetic cooling of two atomic isotopes is experimentally investigated. Using forced evaporation of a bosonic 7 Li gas in a magnetic trap, a sample of 3 10 5 6 Li fermions has been sympathetically cooled to 9(3) µK, corresponding to 2.2(0.8) times the Fermi temperature. The measured rate constant for 2-body inelastic collisions of 7 Li |2, 2 state at low magnetic field is 1.0

Cooling and Trapping a Bose-Fermi Mixture of Dilute Atomic Gases