Heteronuclear quantum gas mixtures

Abstract

Abstract. In this PhD tutorial article, we present experiments with quantum degenerate mixtures of fermionic and bosonic atoms in 3-dimensional optical lattices. This heteronuclear quantum gas mixture offers a wide range of possibilities for quantum simulation, implementation of condensed matter Hamiltonians, quantum chemistry and ultimately dense and quantum degenerate dipolar molecular samples.We When loaded into a 3D optical lattice, a whole zoo of novel quantum phases has been predicted for Fermi-Bose mixtures. We present the first realization of Fermi-Bose mixtures in 3D optical lattices as a novel quantum many body system [3]. We study the phase coherence of the bosonic cloud in the 3D optical lattice as a function of the amount of fermionic atoms simultaneously trapped in the lattice. We observe a loss of phase coherence at much lower lattice depth than for a pure bosonic cloud and discuss possible theoretical scenarios including adiabatic processes, mean field FermiBose Hubbard scenarios, and disorder-enhanced localization scenarios.After considering this many-body limit of mixtures in lattices, we show how fermionic heteronuclear Feshbach molecules can be created in the optical lattice [4] as a crucial step towards all ground state dense dipolar molecular samples. We develop rf association as a novel molecule association technique, measure the binding energy, lifetime, and association efficiency of the molecules. We develop a simple theoretical single channel model of the molecules trapped in the lattice [5] which gives excellent quantitative agreement with the experimental data.

Yang-Yang thermodynamics of a Bose-Fermi mixture

“…The interaction in the mixture, on the other hand, may be enhanced greatly by the so-called confinement induced resonances [5]. Additionally, all interactions can be tuned using available Bose-Fermi Feshbach resonances [22]. In Fig.…”

Tune-out wavelengths of alkali-metal atoms and their applications

“…The realization of mixtures of trapped ultracold atomic gases [1][2][3][4][5] has opened new paths towards the formation of ultracold diatomic molecules [6][7][8][9][10], quantumstate control of chemical reactions [11], prospects for quantum computing with polar molecules [12][13][14], tests of fundamental symmetries [15][16][17] and studies of fundamental aspects of correlated many-body systems [18], and dilute quantum degenerate systems [19][20][21][22][23]. Cotrapped diamagnetic-paramagnetic mixtures have also made possible experimental realization of interspecies Feshbach resonances [24][25][26], two-species Bose-Einstein condensates and mixed Bose-Fermi and Fermi-Fermi degenerate gases [18,[27][28][29].…”

Localization of Bosonic Atoms by Fermionic Impurities in a Three-Dimensional Optical Lattice

“…Our experimental procedure for creating degenerate mixtures has been described previously [24,25]. In brief, we create Fermi-Bose mixtures by first collecting and precooling bosonic 87 Rb and fermionic 40 K atoms using a combined 2D-3D magneto-optical trap laser cooling system.…”