Littérature scientifique sur le sujet « Mass-imbalanced Fermi mixtures »

We study spin- and mass-imbalanced mixtures of spin-1/2 fermions interacting via an attractive contact potential in one spatial dimension. Specifically, we address the influence of unequal particle masses on the pair formation by means of the complex Langevin method. By computing the pair-correlation function and the associated pair-momentum distribution we find that inhomogeneous pairing is present for all studied spin polarizations and mass imbalances. To further characterize the pairing behavior, we analyze the density-density correlations in momentum space, the so-called shot noise, which is experimentally accessible through time-of-flight imaging. At finite spin polarization, the latter is known to show distinct maxima at momentum configurations associated with the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) instability. Besides those maxima, we find that additional features emerge in the noise correlations when mass imbalance is increased, revealing the stability of FFLO-type correlations against mass imbalance and furnishing an experimentally accessible signature to probe this type of pairing.

The thesis reports on the design and implementation of a novel experimental apparatus for the realization and investigation of ultracold Fermi-Fermi mixtures of Cr-53 and Li-6 atoms. After a brief introduction to the physics of ultracold Fermi gases with tunable interactions, the manuscript also reports on the exceptional peculiarities and unprecedented potentiality of the Cr-Li mixture. The thesis describes the first realization and investigation of magneto-optically trapped cold clouds of Cr and Li atoms worldwide. Furthermore, the thesis also reports on the study of normal and superfluid fermionic currents of Li-6 atoms through a thin Josephson junction across the BEC-BCS crossover. The study led to the extraction of the critical values of particle imbalance across the junction beyond which dissipative dynamics is established.