Quantum shock waves and population inversion in collisions of ultracold atomic clouds

Quantum dynamics of ultracold Na+ Na2 collisions.

Ultracold collisions between spin-polarized Na atoms and vibrationally excited Na2 molecules are investigated theoretically, using a reactive scattering formalism (including atom exchange). Calculations are carried out on both pairwise additive and nonadditive potential energy surfaces for the quartet electronic state. The Wigner threshold laws are followed for energies below 10(-5) K. Vibratio...

Quantum state control via trap-induced shape resonance in ultracold atomic collisions.

We investigate controlled collisions between trapped but separated ultracold atoms. The interaction between atoms is treated self-consistently using an energy-dependent delta-function pseudopotential model, whose validity we establish. At a critical separation, a "trap-induced shape resonance" between molecular bound states and a vibrational eigenstate of the trap can occur. This resonance lead...

Ultracold-atom collisions in atomic waveguides : A two-channel analysis

Ultracold atomic quantum gases far from equilibrium

We calculate the time evolution of a far-from-equilibrium initial state of a non-relativistic ultracold Bose gas in one spatial dimension. The non-perturbative approximation scheme is based on a systematic expansion of the two-particle irreducible effective action in powers of the inverse number of field components. This yields dynamic equations which contain direct scattering, memory and off-s...

Implementing quantum electrodynamics with ultracold atomic systems

Wediscuss the experimental engineering ofmodel systems for the description of quantum electrodynamics (QED) in one spatial dimension via amixture of bosonic Na and fermionic Li atoms. The local gauge symmetry is realized in an optical superlattice, using heteronuclear boson– fermion spin-changing interactions which preserve the total spin in every local collision.We consider a large number of b...