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:cond-mat/0304534 · Physical Review Letters

Supersolid versus Phase Separation in Atomic Bose-Fermi Mixtures

Hans Peter Büchler, G. Blatter

Published Sep 25, 2003• 191 citations
arXivHTMLPDF

Abstract

We show that a two-dimensional atomic mixture of bosons and fermions cooled into their quantum degenerate states and subject to an optical lattice develops a supersolid phase characterized by the simultaneous presence of a nontrivial crystalline order and phase order. This transition is in competition with phase separation. We determine the phase diagram of the system and propose an experiment allowing for the observation of the supersolid phase.

DOI
10.1103/physrevlett.91.130404

Related papers

Supersolidity of cold-atom Bose-Fermi mixtures in optical lattices

Peter P. Orth, Doron L. Bergman, Karyn Le Hur

We investigate a cold-atom mixture of spinless bosons and fermions in two-dimensional optical lattices. In the presence of a nested Fermi surface, the bosons may develop a fascinating supersolid behavior characterized by a finite superfluid density as well as a spatial density wave order. Focusing on the triangular lattice geometry and combining a general Landau-Ginzburg-Wilson approach with microscopically derived mean-field theory, we find an exotic supersolid phase at a fermionic band filling of ${n}_{f}=3∕4$ with a kagome-type crystalline order. We also address the case of anisotropic hopping amplitudes and show that striped supersolid phases emerge on the square and triangular lattices. For weak interactions, the supersolid competes with phase separation. For strong intraspecies and interspecies interactions, with the total number of fermions and bosons corresponding to one particle per site, the bosons form an alternating Mott insulator ground state. Finally, for a mixture of $^{87}\mathrm{Rb}^{40}\mathrm{K}$ and $^{23}\mathrm{Na}^{6}\mathrm{Li}$, we show that supersolidity can be observed in the range of accessible temperatures in the square lattice geometry.

arXiv:0905.1125•Physical Review A•Aug 28, 2009•36 citations

Phase separation of atomic Bose-Fermi mixtures in an optical lattice

Hans Peter Büchler, G. Blatter

We study a two-dimensional atomic mixture of bosons and fermions cooled into their quantum degenerate states and subject to an optical lattice. The optical lattice provides van Hove singularities in the fermionic density of states. We find that these van Hove singularities produce new and interesting features for the transition towards phase separation: an arbitrary weak interaction between the bosons and the fermions is sufficient to drive the phase separation at low temperatures. The phase-separated state turns stable for attractive and repulsive interactions between the bosons and fermions and can be cast into the standard form of a ``liquid--gas'' transition.

arXiv:cond-mat/0402432•Physical Review A•Jun 8, 2004•52 citations

Quantum phases of atomic boson-fermion mixtures in optical lattices

Robert Roth, Keith R. Burnett

The zero-temperature phase diagram of a binary mixture of bosonic and fermionic atoms in a one-dimensional optical lattice is studied in the framework of the Bose-Fermi-Hubbard model. By exact numerical solution of the associated eigenvalue problems, ground state observables and the response to an external phase twist are evaluated. The stiffnesses under phase variations provide measures for the boson superfluid fraction and the fermionic Drude weight. Several distinct quantum phases are identified as functions of the strength of the repulsive boson-boson and the boson-fermion interactions. In addition to the bosonic Mott-insulator phase, two other insulating phases are found, where both the bosonic superfluid fraction and the fermionic Drude weight vanish simultaneously. One of these double-insulator phases exhibits a crystalline diagonal long-range order, while the other is characterized by spatial separation of the two species.

arXiv:cond-mat/0310114•Physical Review A•Feb 26, 2004•83 citations

Supersolids in one-dimensional Bose-Fermi mixtures

F. Hébert, G. G. Batrouni, X. Roy +1 more

Using quantum Monte Carlo simulations, we study a mixture of bosons and fermions loaded on an optical lattice. With simple on-site repulsive interactions, this system can be driven into a solid phase. We dope this phase and, in analogy with pure bosonic systems, identify the conditions under which the bosons enter a supersolid phase, i.e., exhibit at the same time charge density-wave and superfluid order. We perform finite-size scaling analysis to confirm the presence of a supersolid phase and discuss its properties, showing that it is a collective phase that also involve phase coherence of the fermions.

arXiv:0808.3321•Physical Review B•Nov 4, 2008•31 citations

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

Bose-Fermi solid and its quantum melting in a one-dimensional optical lattice

Bin Wang, Daw-Wei Wang, S. Das Sarma

We investigate the quantum phase diagram of Bose-Fermi mixtures of ultracold dipolar particles trapped in one-dimensional optical lattices in the thermodynamic limit. With the presence of nearest-neighbor (NN) interactions, a long-ranged ordered crystalline phase (Bose-Fermi solid) is found stabilized in the limit of weak intersite tunneling ($J$). When $J$ is increased, such a Bose-Fermi solid can be quantum melted into a Bose-Fermi liquid through different procedures, depending on whether the crystalline order is dominated by the NN interaction between fermions or bosons. These properties are qualitatively different from the classical picture of solid-liquid phase transition.

arXiv:1004.5129•Physical Review A•Aug 10, 2010•8 citations
We show that a two-dimensional atomic mixture of bosons and fermions cooled into their quantum degenerate states and subject to an optical lattice develops a supersolid phase characterized by the simultaneous presence of a nontrivial crystalline order and phase order. This transition is in competition with phase separation. We determine the phase diagram of the system and propose an experiment allowing for the observation of the supersolid phase.
We investigate a cold-atom mixture of spinless bosons and fermions in two-dimensional optical lattices. In the presence of a nested Fermi surface, the bosons may develop a fascinating supersolid behavior characterized by a finite superfluid density as well as a spatial density wave order. Focusing on the triangular lattice geometry and combining a general Landau-Ginzburg-Wilson approach with microscopically derived mean-field theory, we find an exotic supersolid phase at a fermionic band filling of nf=3∕4{n}_{f}=3∕4nf​=3∕4 with a kagome-type crystalline order. We also address the case of anisotropic hopping amplitudes and show that striped supersolid phases emerge on the square and triangular lattices. For weak interactions, the supersolid competes with phase separation. For strong intraspecies and interspecies interactions, with the total number of fermions and bosons corresponding to one particle per site, the bosons form an alternating Mott insulator ground state. Finally, for a mixture of 87Rb40K^{87}\mathrm{Rb}^{40}\mathrm{K}87Rb40K and 23Na6Li^{23}\mathrm{Na}^{6}\mathrm{Li}23Na6Li, we show that supersolidity can be observed in the range of accessible temperatures in the square lattice geometry.
We study a two-dimensional atomic mixture of bosons and fermions cooled into their quantum degenerate states and subject to an optical lattice. The optical lattice provides van Hove singularities in the fermionic density of states. We find that these van Hove singularities produce new and interesting features for the transition towards phase separation: an arbitrary weak interaction between the bosons and the fermions is sufficient to drive the phase separation at low temperatures. The phase-separated state turns stable for attractive and repulsive interactions between the bosons and fermions and can be cast into the standard form of a ``liquid--gas'' transition.
The zero-temperature phase diagram of a binary mixture of bosonic and fermionic atoms in a one-dimensional optical lattice is studied in the framework of the Bose-Fermi-Hubbard model. By exact numerical solution of the associated eigenvalue problems, ground state observables and the response to an external phase twist are evaluated. The stiffnesses under phase variations provide measures for the boson superfluid fraction and the fermionic Drude weight. Several distinct quantum phases are identified as functions of the strength of the repulsive boson-boson and the boson-fermion interactions. In addition to the bosonic Mott-insulator phase, two other insulating phases are found, where both the bosonic superfluid fraction and the fermionic Drude weight vanish simultaneously. One of these double-insulator phases exhibits a crystalline diagonal long-range order, while the other is characterized by spatial separation of the two species.
Using quantum Monte Carlo simulations, we study a mixture of bosons and fermions loaded on an optical lattice. With simple on-site repulsive interactions, this system can be driven into a solid phase. We dope this phase and, in analogy with pure bosonic systems, identify the conditions under which the bosons enter a supersolid phase, i.e., exhibit at the same time charge density-wave and superfluid order. We perform finite-size scaling analysis to confirm the presence of a supersolid phase and discuss its properties, showing that it is a collective phase that also involve phase coherence of the fermions.
We investigate the quantum phase diagram of Bose-Fermi mixtures of ultracold dipolar particles trapped in one-dimensional optical lattices in the thermodynamic limit. With the presence of nearest-neighbor (NN) interactions, a long-ranged ordered crystalline phase (Bose-Fermi solid) is found stabilized in the limit of weak intersite tunneling (JJJ). When JJJ is increased, such a Bose-Fermi solid can be quantum melted into a Bose-Fermi liquid through different procedures, depending on whether the crystalline order is dominated by the NN interaction between fermions or bosons. These properties are qualitatively different from the classical picture of solid-liquid phase transition.