Correlated fermions on a checkerboard lattice.

  title={Correlated fermions on a checkerboard lattice.},
  author={F. Pollmann and Joseph J. Betouras and Kirill Shtengel and Peter Fulde},
  journal={Physical review letters},
  volume={97 17},
A model of strongly correlated spinless fermions on a checkerboard lattice is mapped onto a quantum fully packed loop model. We identify a large number of fluctuationless states specific to the fermionic case. We also show that for a class of fluctuating states the fermionic sign problem can be gauged away. This claim is supported by numerical evaluation of the low-lying states. Furthermore, we analyze excitations at the Rokhsar-Kivelson point of this model using the relation to the height… 
Systems of strongly correlated fermions on certain geometrically frustrated lattices at particular filling factors support excitations with fractional charges ±e/2. We calculate quantum mechanical
A two-band model for superconductivity in the checkerboard lattice.
An electronic model on a checkerboard lattice, which can be viewed as a two-dimensional analog of the pyrochlore lattice is proposed, treated via a Bardeen-Cooper-Schrieffer (BCS) approximation, decoupling the interaction terms in real space.
Strings in strongly correlated electron systems
It is shown that strongly correlated electrons on frustrated lattices like pyrochlore, checkerboard or kagomè lattice can lead to the appearance of closed and open strings. They are resulting from
Supersymmetric lattice fermions on the triangular lattice: superfrustration and criticality
We study a model for itinerant, strongly interacting fermions where a judicious tuning of the interactions leads to a supersymmetric Hamiltonian. On the triangular lattice this model is known to
Frustration effects in an anisotropic checkerboard lattice Hubbard model
We study the ground-state properties of the geometrically frustrated Hubbard model on the anisotropic checkerboard lattice with nearest-neighbor hopping $t$ and next-nearest-neighbor hopping
Charge degrees of freedom on the kagome lattice
Within condensed matter physics, systems with strong electronic correlations give rise to fascinating phenomena which characteristically require a physical description beyond a one-electron theory,
Mobile holes in frustrated quantum magnets and itinerant fermions on frustrated geometries
At commensurate electron fillings and in the presence of strong Coulomb repulsion, geometrical frustration can also manifests itself as an extensive degeneracy of the classical ground-state manifold providing profound similarities with the field of quantum frustrated magnetism.
Large-amplitude superexchange of high-spin fermions in optical lattices
We show that fermionic high-spin systems with spin-changing collisions allow one to monitor superexchange processes in optical superlattices with large amplitudes and strong spin fluctuations. By
Where Do Braid Statistics and Discrete Motion Meet Each Other?
Abstract We consider universal statistical properties of systems that are characterized by phase states with macroscopic degeneracy of the ground state. A possible topological order in such systems
High-dimensional fractionalization and spinon deconfinement in pyrochlore antiferromagnets
The ground states of Klein type spin models on the pyrochlore and checkerboard lattice are spanned by the set of singlet dimer coverings, and thus possess an extensive ground--state degeneracy. Among


Exact results for strongly correlated fermions in 2 + 1 dimensions.
By exploiting supersymmetry, the number and type of ground states exactly are found and the model is in an exotic "superfrustrated" state characterized by an extensive ground-state entropy.
On confined fractional charges : A simple model
We address the question whether features known from quantum chromodynamics (QCD) can possibly also show up in solid-state physics. It is shown that spinless fermions of charge e on a checkerboard
Charge degrees of freedom in frustrated lattice structures
We study numerically spinless fermions with strong nearest-neighbor repulsion V on frustrated lattice structures which show macroscopically many ground state in the absence of a kinetic energy term
Resonating plaquette phase of a quantum six-vertex model.
In addition to finding a new quantum state, it is shown that the DDW is robust against a class of quantum fluctuations of its order parameter, and the inferred finite temperature phase diagram contains unsuspected multicritical points.
Quantum dimer model on the kagome lattice: solvable dimer-liquid and ising gauge theory.
This work introduces quantum dimer models on lattices made of corner-sharing triangles, which realize fully disordered and gapped dimer-liquid phase with topological degeneracy and deconfined fractional excitations, as well as solid phases.
Cyclic exchange, isolated states and spinon deconfinement in an XXZ Heisenberg model on the checkerboard lattice
The antiferromagnetic Ising model on a checkerboard lattice has an ice-like ground state manifold with extensive degeneracy. and, to leading order in ${J}_{xy}$, deconfined spinon excitations. We
Microscopic models of two-dimensional magnets with fractionalized excitations
We demonstrate that spin-charge separation can occur in two dimensions and note its confluence with superconductivity, topology, gauge theory, and fault-tolerant quantum computation. We construct a
We consider the nature of superconductivity near a spin-liquid state with a large spin-excitation-gap. We argue that the quantum-dimer-model with holes is a good approximation in this limit. The
Quantum dimer model with extensive ground-state entropy on the kagome lattice
We introduce a quantum dimer model on the kagome lattice with kinetic terms allowing from three to six dimers to resonate around hexagons. Unlike the models studied previously, the different
Resonating valence bond phase in the triangular lattice quantum dimer model.
The quantum dimer model on the triangular lattice is studied, which is expected to describe the singlet dynamics of frustrated Heisenberg models in phases where valence bond configurations dominate their physics, and it is found that there is a truly short ranged resonating valence Bond phase with no gapless excitations and with deconfined, gapped, spinons for a finite range of parameters.