2006/01/12 by E. Orignac, Edmond Orignac, R. Citro +1
Physics and Astronomy · #Boson #Bosonization #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Fermion #Feshbach resonance #Hamiltonian (control theory) #Physics #Physics of Superconductivity and Magnetism #Quantum electrodynamics #Quantum mechanics #Quantum, superfluid, helium dynamics #Quasiparticle #Superconductivity #Superfluidity #cond-mat.mes-hall #cond-mat.other
paper · pdf · doi:10.1103/physreva.73.063611
published as Phys. Rev. A 73, 063611 (2006) · 31 pages, 8 EPS figures, RevTeX 4, long version of cond-mat/0505706
arxiv created 2006/01/12 · openalex publication_date 2006/06/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study one-dimensional fermions with photoassociation or with a narrow Fano-Feshbach resonance described by the boson-fermion resonance model. Using the bosonization technique, we derive a low-energy Hamiltonian of the system. We show that at low energy, the order parameters for the Bose condensation and fermion superfluidity become identical, while a spin gap and a gap against the formation of phase slips are formed. As a result of these gaps, charge density wave correlations decay exponentially in contrast with the phases where only bosons or only fermions are present. We find a Luther-Emery point where the phase slips and the spin excitations can be described in terms of pseudofermions. This allows us to provide closed form expressions of the density-density correlations and the spectral functions. The spectral functions of the fermions are gapped, whereas the spectral functions of the bosons remain gapless. The application of a magnetic field results in a loss of coherence between the bosons and the fermion and the disappearance of the gap. Changing the detuning has no effect on the gap until either the fermion or the boson density is reduced to zero. Finally, we discuss the formation of a Mott insulating state in a periodic potential. The relevance of our results for experiments with ultracold atomic gases subject to one-dimensional confinement is also discussed.