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

Physical Review B

Critical behavior of the single-particle spectral weight in the ionic Hubbard model

M. C. Refolio, J. M. Lòpez Sancho, J. Rubio

Published Jul 15, 2005• 1 citation
Publisher

Abstract

We show in this paper that the single-particle spectral-weight function (SWF) of the one-dimensional ionic Hubbard model at half filling exhibits critical behavior, as a function of the on-site repulsion $U$, near the chemical potential. The calculation has been carried out within the framework of the cluster perturbation theory approach of Senechal et al., Phys. Rev. Lett 84, 522 (2000). As $U$ increases, the SWF at ${k}_{F}=\ifmmode\pm\else\textpm\fi{}\ensuremath{\pi}∕2$ (the Fermi points) jumps from the two-peak structure (plus two weak side peaks) characteristic of low $U<{U}_{c}$ to a four-peak structure beyond ${U}_{c}$ where all the peaks have about the same spectral weight. This abrupt spectral-weight transfer from the inner to the outer peaks can be traced to the ionic-neutral transition characteristic of this system and seems to correspond to the first critical point of the two-point scenario discussed in the literature. It is accompanied by a nonvanishing minimum of the single-particle charge gap. As $U$ increases further, the system evolves gradually into a Mott-Hubbard insulator. No other signatures of abrupt change are detected in the SWF. These results are discussed in the light of photoelectron spectroscopic measurements of quasi-one-dimensional materials.

DOI
10.1103/physrevb.72.035121

Related papers

The one-particle Green's function of one.dimensional insulating materials

M. C. Refolio, Sancho, J. M. Lopez, Rubio, J. +1 more

The single particle spectral-weight function (SWF) of the ionic Hubbard model at half filling is calculated in the cluster perturbation theory approximation. An abrupt change of regime in the low-energy region, near the chemical potential, is found at a critical value, $U_{c}$, of the coupling constant (Hubbard $U$). The SWF at the Fermi points $k_{F}$=$\pmπ/2$ jumps, as $U$ increases, from a two-peak structure, the gap edges, to a four-peak structure accompanied by a (non-vanishing) minimum of the charge-gap. The two inner peaks of this structure show very small dispersion (flat bands) away from the Fermi points, whereas the outer peaks mark the edges of the Hubbard bands. No other signatures of abrupt change are detected in the SWF. The two regimes are physically realized in the angle-resolved photoelectron spectra of $(TaSe_{4})_{2}I$, and the blue-bronze $K_{0.3}MoO_{3}$, respectively.

arXiv:cond-mat/0412565•Dec 21, 2004•0 citations

Spectral-weight function of the ionic Hubbard model

M. C. Refolio, Sancho, J. M. Lopez, Rubio, J.

The one-electron spectral-weight function of the half-filled ionic Hubbard model is calculated by means of Quantum Monte Carlo. A metallic regimen occurs between two values of the coupling constant (Hubbard U) U1 < U2 . The system is a band insulator below U1, and an increasingly antiferromagnetic (AF) insulator above U2 evolving into a Mott insulator as U tends to infinity . The intermediate regimen which is both AF and dimerized, is caused by a two-peak structure at k = 0,5 pi (the Fermi surface). As U increases both peaks approach each other, overlap, and separate again, the system becoming metallic in the overlap region.

arXiv:cond-mat/0210462•Oct 21, 2002•0 citations

Quantum critical behavior of the one-dimensional ionic Hubbard model

Salvatore R. Manmana, V. Meden, R. M. Noack +1 more

We study the zero-temperature phase diagram of the half-filled one-dimensional ionic Hubbard model. This model is governed by the interplay of the on-site Coulomb repulsion and an alternating one-particle potential. Various many-body energy gaps, the charge-density-wave and bond-order parameters, the electric as well as the bond-order susceptibilities, and the density-density correlation function are calculated using the density-matrix renormalization group method. In order to obtain a comprehensive picture, we investigate systems with open as well as periodic boundary conditions and study the physical properties in different sectors of the phase diagram. A careful finite-size scaling analysis leads to results which give evidence in favor of a scenario with two quantum critical points and an intermediate spontaneously dimerized phase. Our results indicate that the phase transitions are continuous. Using a scaling ansatz we are able to read off critical exponents at the first critical point. In contrast to a bosonization approach, we do not find Ising critical exponents. We show that the low-energy physics of the strong-coupling phase can only partly be understood in terms of the strong-coupling behavior of the ordinary Hubbard model.

arXiv:cond-mat/0307741•Physical Review B•Oct 29, 2004•117 citations

One-electron spectral weight of the doped two-dimensional Hubbard model

Niyazi Bulut, Douglas J. Scalapino, Steven R. White

We have calculated the single-particle density of states N(\ensuremath{\omega}) and the spectral weight A(p,\ensuremath{\omega}) for the doped two-dimensional Hubbard model by combining quantum Monte Carlo simulations with the maximum-entropy analytic continuation technique. We present results for various values of the doping, temperature, and Coulomb repulsion U. For sufficiently strong Coulomb repulsions and near half filling, a Mott-Hubbard pseudogap exists. In this case, we find that a peak develops at the top of the lower Hubbard band near the Fermi level at temperatures of order of the hopping t. The structure of this peak is similar to that seen in the infinite dimensional Hubbard model.

Physical Review Letters•Jan 31, 1994•100 citations

Phase transitions and spectral properties of the ionic Hubbard model in one dimension

Ara Go, Gun Sang Jeon

The ionic Hubbard model is investigated at half filling at zero temperature. We apply the cellular dynamical mean-field theory to the one-dimensional ionic Hubbard model to compute local quantities such as double occupancy and staggered charge density. Both quantities provide general transition behavior of the model from a band insulating phase to a Mott insulating phase. The renormalized band gap is introduced as an efficient order parameter for the transition from a band insulator. We also present the spectral properties of the ionic Hubbard model, which exhibit characteristic features for both weak and strong interactions.

arXiv:1111.1119•Physical Review B•Nov 3, 2011•16 citations

Transport criticality at the Mott transition in a triangular-lattice Hubbard model

Toshihiro Sato, Kazumasa Hattori, Hirokazu Tsunetsugu

We study electric transport near the Mott metal-insulator transition in a triangular-lattice Hubbard model at half filling. We calculate optical conductivity $\ensuremath{\sigma}(\ensuremath{\omega})$ based on a cellular dynamical mean-field theory including vertex corrections inside the cluster. Near the Mott critical end point, a Drude analysis in the metallic region suggests that the change in the Drude weight is important rather than that in the transport scattering rate for the Mott transition. In the insulating region, there emerges an ``in-gap'' peak in $\ensuremath{\sigma}(\ensuremath{\omega})$ at low $\ensuremath{\omega}$ near the Mott transition, and this smoothly connects to the Drude peak in the metallic region with decreasing Coulomb repulsion. We find that the weight of these peaks exhibits a power-law behavior upon controlling Coulomb repulsion at the critical temperature. The obtained critical exponent suggests that conductivity does not correspond to magnetization or energy density of the Ising universality class in contrast to several previous works.

arXiv:1212.1227•Physical Review B•Dec 21, 2012•17 citations
We show in this paper that the single-particle spectral-weight function (SWF) of the one-dimensional ionic Hubbard model at half filling exhibits critical behavior, as a function of the on-site repulsion UUU, near the chemical potential. The calculation has been carried out within the framework of the cluster perturbation theory approach of Senechal et al., Phys. Rev. Lett 84, 522 (2000). As UUU increases, the SWF at kF=\ifmmode±\else\textpm\fi\ensuremathπ∕2{k}_{F}=\ifmmode\pm\else\textpm\fi{}\ensuremath{\pi}∕2kF​=\ifmmode±\else\textpm\fi\ensuremathπ∕2 (the Fermi points) jumps from the two-peak structure (plus two weak side peaks) characteristic of low U<UcU<{U}_{c}U<Uc​ to a four-peak structure beyond Uc{U}_{c}Uc​ where all the peaks have about the same spectral weight. This abrupt spectral-weight transfer from the inner to the outer peaks can be traced to the ionic-neutral transition characteristic of this system and seems to correspond to the first critical point of the two-point scenario discussed in the literature. It is accompanied by a nonvanishing minimum of the single-particle charge gap. As UUU increases further, the system evolves gradually into a Mott-Hubbard insulator. No other signatures of abrupt change are detected in the SWF. These results are discussed in the light of photoelectron spectroscopic measurements of quasi-one-dimensional materials.
The single particle spectral-weight function (SWF) of the ionic Hubbard model at half filling is calculated in the cluster perturbation theory approximation. An abrupt change of regime in the low-energy region, near the chemical potential, is found at a critical value, UcU_{c}Uc​, of the coupling constant (Hubbard UUU). The SWF at the Fermi points kFk_{F}kF​=±π/2\pmπ/2±π/2 jumps, as UUU increases, from a two-peak structure, the gap edges, to a four-peak structure accompanied by a (non-vanishing) minimum of the charge-gap. The two inner peaks of this structure show very small dispersion (flat bands) away from the Fermi points, whereas the outer peaks mark the edges of the Hubbard bands. No other signatures of abrupt change are detected in the SWF. The two regimes are physically realized in the angle-resolved photoelectron spectra of (TaSe4)2I(TaSe_{4})_{2}I(TaSe4​)2​I, and the blue-bronze K0.3MoO3K_{0.3}MoO_{3}K0.3​MoO3​, respectively.
The one-electron spectral-weight function of the half-filled ionic Hubbard model is calculated by means of Quantum Monte Carlo. A metallic regimen occurs between two values of the coupling constant (Hubbard U) U1 < U2 . The system is a band insulator below U1, and an increasingly antiferromagnetic (AF) insulator above U2 evolving into a Mott insulator as U tends to infinity . The intermediate regimen which is both AF and dimerized, is caused by a two-peak structure at k = 0,5 pi (the Fermi surface). As U increases both peaks approach each other, overlap, and separate again, the system becoming metallic in the overlap region.
We study the zero-temperature phase diagram of the half-filled one-dimensional ionic Hubbard model. This model is governed by the interplay of the on-site Coulomb repulsion and an alternating one-particle potential. Various many-body energy gaps, the charge-density-wave and bond-order parameters, the electric as well as the bond-order susceptibilities, and the density-density correlation function are calculated using the density-matrix renormalization group method. In order to obtain a comprehensive picture, we investigate systems with open as well as periodic boundary conditions and study the physical properties in different sectors of the phase diagram. A careful finite-size scaling analysis leads to results which give evidence in favor of a scenario with two quantum critical points and an intermediate spontaneously dimerized phase. Our results indicate that the phase transitions are continuous. Using a scaling ansatz we are able to read off critical exponents at the first critical point. In contrast to a bosonization approach, we do not find Ising critical exponents. We show that the low-energy physics of the strong-coupling phase can only partly be understood in terms of the strong-coupling behavior of the ordinary Hubbard model.
We have calculated the single-particle density of states N(\ensuremath{\omega}) and the spectral weight A(p,\ensuremath{\omega}) for the doped two-dimensional Hubbard model by combining quantum Monte Carlo simulations with the maximum-entropy analytic continuation technique. We present results for various values of the doping, temperature, and Coulomb repulsion U. For sufficiently strong Coulomb repulsions and near half filling, a Mott-Hubbard pseudogap exists. In this case, we find that a peak develops at the top of the lower Hubbard band near the Fermi level at temperatures of order of the hopping t. The structure of this peak is similar to that seen in the infinite dimensional Hubbard model.
The ionic Hubbard model is investigated at half filling at zero temperature. We apply the cellular dynamical mean-field theory to the one-dimensional ionic Hubbard model to compute local quantities such as double occupancy and staggered charge density. Both quantities provide general transition behavior of the model from a band insulating phase to a Mott insulating phase. The renormalized band gap is introduced as an efficient order parameter for the transition from a band insulator. We also present the spectral properties of the ionic Hubbard model, which exhibit characteristic features for both weak and strong interactions.
We study electric transport near the Mott metal-insulator transition in a triangular-lattice Hubbard model at half filling. We calculate optical conductivity $\ensuremath{\sigma}(\ensuremath{\omega})$ based on a cellular dynamical mean-field theory including vertex corrections inside the cluster. Near the Mott critical end point, a Drude analysis in the metallic region suggests that the change in the Drude weight is important rather than that in the transport scattering rate for the Mott transition. In the insulating region, there emerges an ``in-gap'' peak in $\ensuremath{\sigma}(\ensuremath{\omega})$ at low $\ensuremath{\omega}$ near the Mott transition, and this smoothly connects to the Drude peak in the metallic region with decreasing Coulomb repulsion. We find that the weight of these peaks exhibits a power-law behavior upon controlling Coulomb repulsion at the critical temperature. The obtained critical exponent suggests that conductivity does not correspond to magnetization or energy density of the Ising universality class in contrast to several previous works.