Pairing and condensation in a resonant Bose-Fermi mixture

Abstract

We study by diagrammatic means a Bose-Fermi mixture, with boson-fermion coupling tuned by a Fano- Feshbach resonance. For increasing coupling, the growing boson-fermion pairing correlations progressively reduce the boson condensation temperature and make it eventually vanish at a critical coupling. Such quantum critical point depends very weakly on the population imbalance and, for vanishing boson densities, coincides with that found for the polaron-molecule transition in a strongly imbalanced Fermi gas, thus bridging two quite distinct physical systems

Feshbach spectroscopy and scattering properties of ultracold Li + Na mixtures

“…Since their first observation [9,10], interspecies Feshbach resonances have been studied in many experiments. Feshbach resonances in Bose-Fermi mixtures give rise to a rich palette of physical phenomena [11][12][13][14][15].…”

Single-particle spectral functions in the normal phase of a strongly attractive Bose-Fermi mixture

“…Recently, there has been an upsurge of interest on resonantly interacting Bose-Fermi mixtures, with several theoretical [1][2][3][4][5][6][7][8][9][10][11][12][13] and experimental [14][15][16][17][18][19][20][21][22] works being devoted to this subject. Calculations with different theoretical approaches have shown that for sufficiently strong attraction, and a density of bosons smaller than the density of fermions, the boson condensation is completely suppressed even at zero temperature in favor of a phase with dominant molecular correlations [1,2,6,8,11,13].…”

“…Calculations with different theoretical approaches have shown that for sufficiently strong attraction, and a density of bosons smaller than the density of fermions, the boson condensation is completely suppressed even at zero temperature in favor of a phase with dominant molecular correlations [1,2,6,8,11,13].…”

“…The analysis of the spectral functions of the present paper will be based on the analytic continuation to the real frequency axis of a T-matrix diagrammatic approach formulated in the imaginary frequency axis, that we have used previously to characterize the phase diagram and thermodynamic quantities of a resonant Bose-Fermi mixture [8,12]. We will find in this way quite a rich spectrum of single-particle excitations.…”

Energy of strongly attractive Bose-Fermi mixtures

“…This complete suppression of condensation occurs even at zero temperature, and is associated with pairing of bosons with fermions into composite fermions. This kind of evolution has been studied already by us with a T-matrix diagrammatic formalism [15,3,6,8] and with the Fixed-Node Diffusion Monte Carlo method [5].…”