Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0809.3426 · Physical Review A

Superfluid and Fermi-liquid phases of Bose-Fermi mixtures in optical lattices

Kaushik Mitra, Carl J. Williams, Carlos A. R. Sá de Melo

Published May 7, 2009• 0 citations
arXivHTMLPDF

Abstract

We describe interacting mixtures of ultracold bosonic and fermionic atoms in harmonically confined optical lattices. For a suitable choice of parameters we study the emergence of superfluid and Fermi-liquid (noninsulating) regions out of Bose-Mott and Fermi-band insulators due to finite boson and fermion hoppings. We obtain the shell structure for the system and show that angular momentum can be transferred to the noninsulating regions from Laguerre-Gaussian beams, which combined with Bragg spectroscopy can reveal all superfluid and Fermi-liquid shells.

DOI
10.1103/physreva.79.055601

Related papers

Energy spectra of ultracold Bose–Fermi mixtures in optical lattices

Han Jiu-Rong, Yufan Wang, Weiqiang Liu

We show the energy band structure of ultracold atomic Bose-Fermi mixtures in optical lattices: two energy bands for bosonic atoms and a single band for fermionic atoms. The energy band structure can determine the superfluid Mott-insulator phase transition. We find the phase diagram of the mixture by means of path integral, and the phase transition depending on the experimental parameters. The possibility of observing these new phases and their transitions in future experiments is discussed.

Journal of Physics B Atomic Molecular and Optical Physics•May 3, 2005•2 citations

Superfluid and Mott-insulating shells of bosons in harmonically confined optical lattices

Kaushik Mitra, Carl J. Williams, C. A. R. Sá de Melo

We describe weakly interacting atomic or molecular bosons trapped in harmonically confined optical lattices, which exhibit a wedding cake structure consisting of insulating (Mott) shells. We show that superfluid regions emerge between Mott shells as a result of fluctuations due to finite hopping and find that the order parameter equation in the superfluid regions is not of the standard Gross-Pitaevskii type except near the insulator-to-superfluid boundaries. We obtain the excitation spectra in the Mott and superfluid regions, and we show that the superfluid shells possess low-energy sound modes with spatially dependent sound velocity described by a local index of refraction directly related to the local superfluid density. Furthermore, we discuss the Berezinskii-Kosterlitz-Thouless transition and vortex-antivortex pairs in thin (wide) superfluid shells (rings) limited by three- (two-) dimensional Mott regions. Last, we propose an experiment to detect superfluid shells using Laguerre-Gaussian beams and Bragg spectroscopy.

arXiv:0711.0029•Physical Review A•Mar 6, 2008•21 citations

Atomic Bose-Fermi Mixtures in an Optical Lattice

Maciej Lewenstein, Luis Santos, M. A. Baranov +1 more

A mixture of ultracold bosons and fermions placed in an optical lattice constitutes a novel kind of quantum gas, and leads to phenomena, which so far has been discussed neither in atomic physics, nor in condensed matter physics. We discuss the phase diagram at low temperatures, and in the limit of strong atom-atom interactions, and predict the existence of quantum phases that involve pairing of fermions with one or more bosons, or, respectively, bosonic holes. The resulting composite fermions may form, depending on the system parameters, a normal Fermi liquid, a density wave, a superfluid liquid, or an insulator with fermionic domains. We discuss the feasibility for observing such phases in current experiments.

arXiv:cond-mat/0306180•Physical Review Letters•Feb 3, 2004•267 citations

Quantum phases of Bose-Fermi mixtures in optical lattices

H. Fehrmann, M. Baranov, Maciej Lewenstein +1 more

We analyze the ground-state phase diagram of an ultracold Bose-Fermi mixture placed in an optical lattice. The quantum phases involve pairing of fermions and one or several bosons. Depending on the physical parameters these composites can form a Fermi liquid, a density wave, a superfluid or a domain insulator. We determine by means of a mean-field formalism the phase boundaries for finite tunneling, and analyze the experimental feasibility of these sort of phases.

Optics Express•Jan 1, 2004•16 citations

Mott insulators and correlated superfluids in ultracold Bose-Fermi mixtures

F. Hébert, Florence Haudin, Lode Pollet +1 more

We study the effects of interaction between bosons and fermions in Bose-Fermi mixtures loaded in an optical lattice. We concentrate on the destruction of a bosonic Mott phase driven by repulsive interaction between bosons and fermions. Once the Mott phase is destroyed, the system enters a superfluid phase where the movements of bosons and fermions are correlated. We show that this phase has simultaneous correlations reminiscent of a conventional superfluid and of a pseudospin density wave order.

arXiv:0706.3799•Physical Review A•Oct 17, 2007•25 citations

Superfluid and Mott-insulator phases of one-dimensional Bose-Fermi mixtures

Aleksander Zujev, A. Baldwin, Richard T. Scalettar +3 more

We study the ground state phases of Bose-Fermi mixtures in one-dimensional optical lattices with quantum Monte Carlo simulations using the canonical worm algorithm. Depending on the filling of bosons and fermions, and the on-site intra- and interspecies interaction, different kinds of incompressible and superfluid phases appear. On the compressible side, correlations between bosons and fermions can lead to a distinctive behavior of the bosonic superfluid density and the fermionic stiffness, as well as of the equal-time Green functions, which allow one to identify regions where the two species exhibit anticorrelated flow. We present here complete phase diagrams for these systems at different fillings and as a function of the interaction parameters.

arXiv:0711.4635•Physical Review A•Sep 26, 2008•30 citations
We describe interacting mixtures of ultracold bosonic and fermionic atoms in harmonically confined optical lattices. For a suitable choice of parameters we study the emergence of superfluid and Fermi-liquid (noninsulating) regions out of Bose-Mott and Fermi-band insulators due to finite boson and fermion hoppings. We obtain the shell structure for the system and show that angular momentum can be transferred to the noninsulating regions from Laguerre-Gaussian beams, which combined with Bragg spectroscopy can reveal all superfluid and Fermi-liquid shells.
We describe weakly interacting atomic or molecular bosons trapped in harmonically confined optical lattices, which exhibit a wedding cake structure consisting of insulating (Mott) shells. We show that superfluid regions emerge between Mott shells as a result of fluctuations due to finite hopping and find that the order parameter equation in the superfluid regions is not of the standard Gross-Pitaevskii type except near the insulator-to-superfluid boundaries. We obtain the excitation spectra in the Mott and superfluid regions, and we show that the superfluid shells possess low-energy sound modes with spatially dependent sound velocity described by a local index of refraction directly related to the local superfluid density. Furthermore, we discuss the Berezinskii-Kosterlitz-Thouless transition and vortex-antivortex pairs in thin (wide) superfluid shells (rings) limited by three- (two-) dimensional Mott regions. Last, we propose an experiment to detect superfluid shells using Laguerre-Gaussian beams and Bragg spectroscopy.
A mixture of ultracold bosons and fermions placed in an optical lattice constitutes a novel kind of quantum gas, and leads to phenomena, which so far has been discussed neither in atomic physics, nor in condensed matter physics. We discuss the phase diagram at low temperatures, and in the limit of strong atom-atom interactions, and predict the existence of quantum phases that involve pairing of fermions with one or more bosons, or, respectively, bosonic holes. The resulting composite fermions may form, depending on the system parameters, a normal Fermi liquid, a density wave, a superfluid liquid, or an insulator with fermionic domains. We discuss the feasibility for observing such phases in current experiments.
We study the ground state phases of Bose-Fermi mixtures in one-dimensional optical lattices with quantum Monte Carlo simulations using the canonical worm algorithm. Depending on the filling of bosons and fermions, and the on-site intra- and interspecies interaction, different kinds of incompressible and superfluid phases appear. On the compressible side, correlations between bosons and fermions can lead to a distinctive behavior of the bosonic superfluid density and the fermionic stiffness, as well as of the equal-time Green functions, which allow one to identify regions where the two species exhibit anticorrelated flow. We present here complete phase diagrams for these systems at different fillings and as a function of the interaction parameters.