Strongly correlated fermions on a kagome lattice

O’Brien, Aroon; Pollmann, Frank; Fulde, Peter

doi:10.1103/physrevb.81.235115

Cited by 78 publications

(77 citation statements)

References 32 publications

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“…The √ 3 × √ 3 reconstruction identified in our mean-field analysis is insofar a reasonable scenario because it maximizes the number of "resonating hexagons" favored by ring exchange processes. Such a behavior would be similar to the one observed in other frustrated models such as the hardcore dimer model on the hexagonal lattice 44 or the frustrated charge models on the kagome 45,46 or checker board lattices. 47 …”

Section: Fo/afmsupporting

confidence: 78%

Electronic structure of (LaNiO3)2/(LaAlO3)
Rüegg
¹
,
Mitra
²
,
Demkov
³

et al. 2012
Phys. Rev. B
77
3
144
0
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The electronic structure of a LaNiO3 bilayer grown along the [111] direction and confined between insulating layers of LaAlO3 is theoretically investigated using a combination of first principle calculations and effective multi-orbital lattice models. The LDA band structure is well reproduced by a tight-binding model for the Ni-eg orbitals defined on the buckled honeycomb lattice. We highlight peculiar properties of this model which include almost flat bands as well as linear and quadratic band crossing points. The effect of local correlations is discussed within the LDA+U scheme and within the Hartree-Fock approximation for interacting multi-orbital lattice models. Over a wide range of interaction parameters we find that a ferromagnetic phase is energetically favored. We discuss the possibility of additional orbital order which could stabilize a spontaneous Chern insulator with chiral edge modes or a staggered orbital phase with a √ 3 × √ 3 reconstruction of the unit cell. By studying an interacting nickel-oxygen lattice model we find that the stability of these orbitally ordered phases also depends on the value of the charge-transfer energy. Controlling the charge-transfer energy might therefore be an important step towards engineering exotic electronic phases in certain classes of oxide heterostructures.

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Section: Fo/afmsupporting

confidence: 78%

Electronic structure of (LaNiO3)2/(LaAlO3)
Rüegg
¹
,
Mitra
²
,
Demkov
³

et al. 2012
Phys. Rev. B
77
3
144
0
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show abstract

“…Indeed, in the classical limit t = 0 and V = 0, the ground state is macroscopically degenerate, and the configurations that minimize the energy obey a rule of two electrons per triangle with one doubly occupied site. A finite t lifts this degeneracy and in the limit t ≪ V the system is effectively described by a hardcore quantum dimer model (QDM) on the honeycomb lattice 11,37,44 whose ground state consists of resonating plaquettes. The mean-field treatment cannot capture the resonating plaquettes of the QDM, but its solution can be thought of as its electrostatic counterpart 10 .…”

Section: Overview Of the Phase Diagrammentioning

confidence: 99%

Phase diagram of the13-filled extended Hubbard model on the kagome lattice

Ferhat

Ralko

2014

Phys. Rev. B

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We study the phase diagram of the extended Hubbard model on the kagome lattice at 1/3 filling. By combining a configuration interaction approach to an unrestricted Hartree-Fock, we construct an effective Hamiltonian which takes the correlations back on top of the mean-field solution. We obtain a rich phase diagram with, in particular, the presence of two original phases. The first one consists of local polarized droplets of metal standing on the hexagons of the lattice, and an enlarged kagome charge order, inversely polarized, on the remaining sites. The second, obeying a local ice-rule type constraint on the triangles of the kagome lattice, is driven by an antiferromagnetically coupling of spins and is constituted of disconnected six-spin singlet rings. The nature and stability of these phases at large interactions are studied via trial wave functions and perturbation theory.

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“…We notice that the spin 1/2 Kagome lattice has been realized in Herbertsmithite ZnCu 3 (OH) 3 26 Also, the optical Kagome lattice has been simulated experimentally in ultra-cold atomic gases, and the optical wavelengths can be suitably adjusted for fermionic isotopes such as 6 Li and 40 K.…”

Section: Summary and Perspectivementioning

confidence: 99%

“…In the Mott insulating limit, several possible states have been proposed as the ground state of the Heisenberg model in this lattice, such as the U (1) algebraic spin liquid (SL), 1 the valance bond solid, 2 the tripletgapped SL, 3 and the singlet-gapped SL with signatures of Z 2 topological order. 4 On the other hand, several exotic phases have been proposed for the Kagome Hubbard model, such as the ferromagnetism at electron filling 1/3 (or 5/3) per site, 5 the fractional charge at 1/3 filling for spinless fermions, 6 and the Mott transition in anisotropic Kagome lattices.…”

Section: Introductionmentioning

confidence: 99%

Competing electronic orders on kagome lattices at van Hove filling

et al. 2013

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The electronic orders in Hubbard models on a Kagome lattice at van Hove filling are of intense current interest and debate. We study this issue using the singular-mode functional renormalization group theory. We discover a rich variety of electronic instabilities under short range interactions. With increasing on-site repulsion U , the system develops successively ferromagnetism, intra unitcell antiferromagnetism, and charge bond order. With nearest-neighbor Coulomb interaction V alone (U = 0), the system develops intra-unit-cell charge density wave order for small V , s−wave superconductivity for moderate V , and the charge density wave order appears again for even larger V . With both U and V , we also find spin bond order and chiral d x 2 −y 2 + idxy superconductivity in some particular regimes of the phase diagram. We find that the s-wave superconductivity is a result of charge density wave fluctuations and the squared logarithmic divergence in the pairing susceptibility. On the other hand, the d-wave superconductivity follows from bond order fluctuations that avoid the matrix element effect. The phase diagram is vastly different from that in honeycomb lattices because of the geometrical frustration in the Kagome lattice.

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Strongly correlated fermions on a kagome lattice

Cited by 78 publications

References 32 publications

Electronic structure of (LaNiO3)2/(LaAlO3)
Rüegg
¹
,
Mitra
²
,
Demkov
³

et al. 2012
Phys. Rev. B
77
3
144
0
View full text Add to dashboard Cite

Electronic structure of (LaNiO3)2/(LaAlO3)
Rüegg
¹
,
Mitra
²
,
Demkov
³

et al. 2012
Phys. Rev. B
77
3
144
0
View full text Add to dashboard Cite

Phase diagram of the13-filled extended Hubbard model on the kagome lattice

Competing electronic orders on kagome lattices at van Hove filling

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Strongly correlated fermions on a kagome lattice

Cited by 78 publications

References 32 publications

Electronic structure of (LaNiO3)2/(LaAlO3)Rüegg1, Mitra2, Demkov3 et al. 2012Phys. Rev. B7731440View full textAdd to dashboardCite

Electronic structure of (LaNiO3)2/(LaAlO3)Rüegg1, Mitra2, Demkov3 et al. 2012Phys. Rev. B7731440View full textAdd to dashboardCite

Phase diagram of the13-filled extended Hubbard model on the kagome lattice

Competing electronic orders on kagome lattices at van Hove filling

Contact Info

Product

Resources

About

Electronic structure of (LaNiO3)2/(LaAlO3)
Rüegg
¹
,
Mitra
²
,
Demkov
³

et al. 2012
Phys. Rev. B
77
3
144
0
View full text Add to dashboard Cite

Electronic structure of (LaNiO3)2/(LaAlO3)
Rüegg
¹
,
Mitra
²
,
Demkov
³

et al. 2012
Phys. Rev. B
77
3
144
0
View full text Add to dashboard Cite