Fermionic Mixtures of Ultracold Atoms: Pairing, Superfluidity and Quantum Phases (FerMix)

Experimental setup at IQOQI

Project summary

Ultracold Fermi gases are at the heart of an emerging research field on strongly interacting quantum matter. New model systems can now be created in the laboratory with superb control of the relevant parameters. Confinement geometries and Fermi energies can be manipulated and, as a unique feature of ultracold gases, the strength of the interparticle interaction can be tuned over a wide range. The research field connects methods from atomic and molecular physics with various other disciplines, like many-body quantum physics and con-densed-matter physics.

A new development in the field of ultracold Fermi gases is to combine different ultracold species and thus to create quantum-degenerate mixtures of two different fermions or mixtures of fermions with bosons. This considerably widens the experimental possibilities and opens up a broad range of intriguing research prospects. The two different species involved can be manipulated independently from each other which e.g. allows for an independent control of the confinement and the relevant Fermi energies. New regimes of fermion pairing become accessible, like pairing beween a heavy and a light fermion or boson-mediated pairing, leading to novel superfluid phases. The exploration of these many-body phenomena will greatly challenge both experimental and theoretical research and will promote the field far beyond the present state of knowledge.

The collaborative research project FerMix focuses European efforts on mixed ultracold Fermi gases by combining strongly interconnected individual projects of leading European researchers with a balance of theoretical and experimental activities. The project is organized along the four main objectives of (i) the preparation of strongly interacting and strongly correlated systems, (ii) studies of new pairing and interaction phenomena, (iii) the exploration of novel regimes of superfluidity, and (iv) studies on novel quantum phases in optical lattices.

Project Leader:

Rudolf Grimm, Institute for Quantum Optics and Quantum Information, AT

Principal Investigators:

Maciej Lewenstein, Institute for Photonic Sciences Barcelona, ES

Christophe Salomon, Ecole Normale Supérieure, FR

Klaus Sengstock, Universität Hamburg, DE

Sandro Stringari, Universita di Trento and INFM, IT

Päivi Törmä, University of Jyväskylä, FI