Drude weight and dc conductivity of correlated electrons

Uhrig, Götz S.; Vollhardt, D.

doi:10.1103/physrevb.52.5617

Cited by 12 publications

(11 citation statements)

References 38 publications

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“…The interpretation of ε b > ω 0 + Σ(ω 0 ) as indication for a binding phenomenon is corroborated by the resulting finite conductivity/mobility σ of the ↓-e − . For T → 0, one has σ ∝ ImG(ω 0 )/ImΣ(ω 0 ) [36]. This is bounded from above according to ImG(ω 0 )/ImΣ(ω 0 ) = ∞ ε b ρ 0 (ω)(ω − ω 0 + Σ(ω 0 )) −2 dω < (ε b − ω 0 + Σ(ω 0 )) −2 .…”

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confidence: 97%

Exact Single Spin Flip for the Hubbard Model ind=∞

Uhrig

1996

Phys. Rev. Lett.

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It is shown that the dynamics of a single ↓-electron interacting with a band of ↑-electrons can be calculated exactly in the limit of infinite dimension. The corresponding Green function is determined as a continued fraction. It is used to investigate the stability of saturated ferromagnetism and the nature of the ground state for two generic non-bipartite infinite dimensional lattices. Non Fermi liquid behavior is found. For certain dopings the ↓-electron is bound to the ↑-holes.

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confidence: 97%

Exact Single Spin Flip for the Hubbard Model ind=∞

Uhrig

1996

Phys. Rev. Lett.

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“…A recent density matrix renormalization group study suggests a generic divergence of σ dc (T ) at low temperatures with σ dc ∝ 1/T [26], different from the Fermi-liquid behavior σ dc ∝ 1/T 2 that emerges in sufficiently high dimensions [44]. For the high-temperature regime, a lower bound for the diffusion constant D has been derived [45], reading…”

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confidence: 99%

Finite-temperature charge transport in the one-dimensional Hubbard model

et al. 2015

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We study the charge conductivity of the one-dimensional repulsive Hubbard model at finite temperature using the method of dynamical quantum typicality, focusing at half filling. This numerical approach allows us to obtain current autocorrelation functions from systems with as many as 18 sites, way beyond the range of standard exact diagonalization. Our data clearly suggest that the charge Drude weight vanishes with a power law as a function of system size. The low-frequency dependence of the conductivity is consistent with a finite dc value and thus with diffusion, despite large finite-size effects. Furthermore, we consider the mass-imbalanced Hubbard model for which the charge Drude weight decays exponentially with system size, as expected for a non-integrable model. We analyze the conductivity and diffusion constant as a function of the mass imbalance and we observe that the conductivity of the lighter component decreases exponentially fast with the mass-imbalance ratio. While in the extreme limit of immobile heavy particles, the Falicov-Kimball model, there is an effective Anderson-localization mechanism leading to a vanishing conductivity of the lighter species, we resolve finite conductivities for an inverse mass ratio of η 0.3.

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“…Since the dc-conductivity in absence of symmetry breaking has been extensively discussed in ref. 26 we will treat here exclusively the case with symmetry breaking. The result of (36) and (37) for weak and strong interaction 27 .…”

Section: Conductivity: Resultsmentioning

confidence: 99%

“…Fermi liquid behavior) are presented in detail in ref. 26 where also the influence of the truncation of the 1/d expansion is discussed.…”

Section: (32c)mentioning

confidence: 99%

Conductivity in a symmetry-broken phase: Spinless fermions with 1/dcorrections

Uhrig

1996

Phys. Rev. B

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The dynamic conductivity σ(ω) of strongly correlated electrons in a symmetry broken phase is investigated in the present work. The model considered consists of spinless fermions with repulsive interaction on a simple cubic lattice. The investigated symmetry broken phase is the charge density wave (CDW) with wave vector Q = (π, π, π) † which occurs at half-filling. The calculations are based on the high dimensional approach, i.e. an expansion in the inverse dimension 1/d is used. The finite dimensionality is accounted for by the inclusion of linear terms in 1/d and the true finite dimensional DOS. Special care is paid to the setup of a conserving approximation in the sense of Baym/Kadanoff without inconsistencies. The resulting Bethe-Salpeter equation is solved for the dynamic conductivity in the non symmetry broken and in the symmetry broken phase (AB-CDW). The dc-conductivity is reduced drastically in the CDW. Yet it does not vanish in the limit T → 0 due to a subtle cancellation of diverging mobility and vanishing DOS. In the dynamic conductivity σ(ω) the energy gap induced by the symmetry breaking is clearly discernible. In addition, the vertex corrections of order 1/d lead to an excitonic resonance lying within the gap.

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Drude weight and dc conductivity of correlated electrons

Cited by 12 publications

References 38 publications

Exact Single Spin Flip for the Hubbard Model ind=∞

Exact Single Spin Flip for the Hubbard Model ind=∞

Finite-temperature charge transport in the one-dimensional Hubbard model

Conductivity in a symmetry-broken phase: Spinless fermions with 1/dcorrections

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