Dispersive spectrum and orbital order of spinless p-band fermions in an optical lattice

Abstract

We study single-particle properties of a spinless p-band correlated fermionic gas in an optical lattice by means of a variational cluster approach (VCA). The single-particle spectral function is almost flat at half-filling and develops a strongly dispersive behavior at lower fillings. The competition between different orbital orderings is studied as a function of filling. We observe that an ``antiferromagnetic'' orbital order develops at half-filling and is destroyed by doping the system evolving into a disordered orbital state. At low filling limit, we discuss the possibility of ``ferromagnetic'' orbital order by complementing the VCA result with observations based on a trial wave function. We also study the behavior of the momentum distribution for different values of the on-site interaction. Finally, we introduce an integration contour in the complex plane which allows to efficiently carry out Matsubara-frequency sums.

published version

References in corpus (21)

• Many-Body Physics with Ultracold Gases
• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Flat bands and Wigner crystallization in the honeycomb optical lattice
• Variational cluster approach to correlated electron systems in low dimensions
• Free fermion antibunching in a degenerate atomic Fermi gas released from an optical lattice
• The $p_{x,y}$-orbital counterpart of graphene: cold atoms in the honeycomb optical lattice
• State preparation and dynamics of ultracold atoms in higher lattice orbitals
• Self-energy-functional approach: Analytical results and the Mott-Hubbard transition
• Variational cluster approach to spontaneous symmetry breaking: The itinerant antiferromagnet in two dimensions
• Atomic matter of non-zero momentum Bose-Einstein condensation and orbital current order
• Orbital ordering and frustration of $p$-band Mott-insulators
• Orbital order in Mott insulators of spinless p-band fermions
• Variational cluster approach to the Hubbard model: Phase-separation tendency and finite-size effects
• Prediction of quantum stripe ordering in optical lattices
• Electron Correlations and the Minority-Spin Band Gap in Half-Metallic Heusler Alloys
• Bond algebraic liquid phase in strongly correlated multiflavor cold atom systems
• Unconventional strongly interacting Bose-Einstein condensates in optical lattices
• Absence of Hole Confinement in Transition Metal Oxides with Orbital Degeneracy
• Mott transition in one dimension: Benchmarking dynamical cluster approaches
• Quantum Antiferromagnetism of Fermions in Optical Lattices with Half-filled p-band
• Magnetism of Cold Fermionic Atoms on p-Band of an Optical Lattice

Cited by in corpus (11)

• Physics of higher orbital bands in optical lattices: a review
• Ferro-Orbitally Ordered Stripes in Systems with Alternating Orbital Order
• Variational cluster approach to thermodynamic properties of interacting fermions at finite temperatures: A case study of the two-dimensional single-band Hubbard model at half filling
• Half-metallicity in NiMnSb: a Variational Cluster Approach with ab-initio parameters
• Comparison of Green's functions for transition metal atoms using self-energy functional theory and coupled-cluster singles and doubles (CCSD)
• Influence of B - site Disorder in $L{a}_{0.5}C{a}_{0.5}M{n}_{1-x}{B}_x{O}_3$ (B = Fe, Ru, Al and Ga) Manganites
• Twisted-bilayer FeSe and the Fe-based superlattices
• Optical conductivity due to orbital polarons in systems with orbital degeneracy
• Topological phases of spinless $p$-orbital fermions in zigzag optical lattices
• Third-order Orbital Corner State and its Realization in Acoustic Crystals
• Phase diagram of strongly attractive $p$-orbital fermions on optical lattices