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

arXiv:cond-mat/0403323 · Physical Review B

Anomalous scaling of conductivity in integrable fermion systems

Peter Prelovšek, Samir El Shawish, X. Zotos, M W Long

Published Nov 29, 2004• 70 citations
arXivHTMLPDF

Abstract

We analyze the high-temperature conductivity in one-dimensional integrable models of interacting fermions: the $t\text{\ensuremath{-}}V$ model (anisotropic Heisenberg spin chain) and the Hubbard model, at half-filling in the regime corresponding to insulating ground state. A microcanonical Lanczos method study for finite size systems reveals anomalously large finite-size effects at low frequencies while a frequency-moment analysis indicates a finite dc conductivity. This phenomenon also appears in a prototype integrable quantum system of impenetrable particles, representing a strong-coupling limit of both models. In the thermodynamic limit, the two results could converge to a finite dc conductivity rather than an ideal conductor or insulator scenario.

DOI
10.1103/physrevb.70.205129

Related papers

Can diffusive and ballistic transport coexist in integrable quantum lattice models

Peter Prelovšek, Marcin Mierzejewski, J. Herbrych

We investigate the high-temperature dynamical conductivity $\sigma(\omega)$ in two one-dimensional integrable quantum lattice models: the anisotropic XXZ spin chain and the Hubbard chain. The emphasis is on the metallic regime of both models, where besides the ballistic component, the regular part of conductivity might reveal a diffusive-like transport. To resolve the low-frequency dynamics, we upgrade the microcanonical Lanczos method enabling studies of finite-size systems with up to $L\leq 32$ sites for XXZ spin model with the frequency resolution $\delta \omega \sim 10^{-3} J$. Results for the XXZ chain reveal a fine structure of $\sigma(\omega)$ spectra, which originates from the discontinuous variation of the stiffness, previously found at commensurate values of the anisotropy parameter $\Delta$. Still, we do not find a clear evidence for a diffusive component, at least not for commensurate values of $\Delta$, particularly for $\Delta =0.5$, as well as for $\Delta \to 0$. Similar is the conclusion for the Hubbard model away from half-filling, where the spectra reveal more universal behavior.

•Jul 6, 2021•0 citations

Coexistence of diffusive and ballistic transport in integrable quantum lattice models

Peter Prelovšek, Marcin Mierzejewski, J. Herbrych

We investigate the high-temperature dynamical conductivity $\ensuremath{\sigma}(\ensuremath{\omega})$ in two one-dimensional integrable quantum lattice models: the anisotropic XXZ spin chain and the Hubbard chain. The emphasis is on the metallic regime of both models, where besides the ballistic component, the regular part of conductivity might reveal a diffusivelike transport. To resolve the low-frequency dynamics, we upgrade the microcanonical Lanczos method enabling studies of finite-size systems with up to $L\ensuremath{\le}32$ sites for the XXZ spin model with the frequency resolution $\ensuremath{\delta}\ensuremath{\omega}\ensuremath{\sim}{10}^{\ensuremath{-}3}J$. Results for the XXZ chain reveal a fine structure of $\ensuremath{\sigma}(\ensuremath{\omega})$ spectra, which originates from the discontinuous variation of the stiffness, previously found at commensurate values of the anisotropy parameter $\mathrm{\ensuremath{\Delta}}$. Still, we do not find clear evidence for a diffusive component, at least not for commensurate values of $\mathrm{\ensuremath{\Delta}}$, particularly for $\mathrm{\ensuremath{\Delta}}=0.5$, as well as for $\mathrm{\ensuremath{\Delta}}\ensuremath{\rightarrow}0$. Similar is the conclusion for the Hubbard model away from half-filling, where the spectra reveal more universal behavior.

arXiv:2107.02454•Physical review. B./Physical review. B•Sep 28, 2021•14 citations

Evidence for ideal insulating or conducting state in a one-dimensional integrable system

X. Zotos, Peter Prelovšek

Using numerical diagonalization techniques we analyze the finite temperature/frequency conductance of a one-dimensional model of interacting spinless fermions. Depending on the interaction, the observed finite temperature charge stiffness and low-frequency conductance indicate a fundamental difference between integrable and nonintegrable cases. The integrable systems behave as ideal conductors in the metallic regime and as ideal insulators in the insulating one. The nonintegrable systems are, as expected, generic conductors in the metallic regime and activated ones in the insulating regime. \textcopyright{} 1996 The American Physical Society.

arXiv:cond-mat/9508078•Physical review. B, Condensed matter•Jan 15, 1996•148 citations

Transport properties of the one-dimensional Hubbard model at finite temperature

Christoph Karrasch, Dante Marvin Kennes, Joel E. Moore

We study finite-temperature transport properties of the one-dimensional Hubbard model using the density matrix renormalization group. Our aim is twofold: First, we compute both the charge- and the spin-current correlation function of the integrable model at half filling. The former decays rapidly, implying that the corresponding Drude weight is either zero or very small. Second, we calculate the optical charge conductivity ${\ensuremath{\sigma}}_{r}eg(\ensuremath{\omega})$ in the presence of small integrability-breaking next-nearest-neighbor interactions (the extended Hubbard model). The dc conductivity is finite and diverges as the temperature is decreased below the gap. Our results thus suggest that the half-filled, gapped Hubbard model is a normal charge conductor at finite temperatures. As a test bed for our numerics, we compute ${\ensuremath{\sigma}}_{r}eg(\ensuremath{\omega})$ for the integrable XXZ spin chain in its gapped phase.

arXiv:1408.1891•Physical Review B•Oct 3, 2014•56 citations

Conductivity in one-dimensional highly correlated electron systems

Norio Kawakami, Sung-Kil Yang

The dc conductivity for the t-J model is exactly obtained at t=J and for the Hubbard model in one dimension. Our calculation is carried out for arbitrary band filling by use of the finite-size-scaling method based on the Bethe-ansatz solution under twisted boundary conditions. The effective transport mass defined as the inverse of the conductivity serves as a sensitive probe of the metal-insulator transition. The effective mass is extremely enhanced near half-filling both for the t-J model at t=J and the repulsive Hubbard model, which is a direct evidence of the metal-insulator transition due to the electron correlation. We observe that the large antiferromagnetic coupling J in the t-J model increases the effective mass. On the other hand, the conductivity in the attractive Hubbard model exhibits quite different properties from the repulsive models.

Physical review. B, Condensed matter•Oct 15, 1991•57 citations

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

Fengping Jin, Robin Steinigeweg, Fabian Heidrich‐Meisner +2 more

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 nonintegrable 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 $\ensuremath{\eta}\ensuremath{\gtrsim}0.25$.

arXiv:1508.01304•Physical Review B•Nov 2, 2015•31 citations
We analyze the high-temperature conductivity in one-dimensional integrable models of interacting fermions: the t\ensuremath-Vt\text{\ensuremath{-}}Vt\ensuremath-V model (anisotropic Heisenberg spin chain) and the Hubbard model, at half-filling in the regime corresponding to insulating ground state. A microcanonical Lanczos method study for finite size systems reveals anomalously large finite-size effects at low frequencies while a frequency-moment analysis indicates a finite dc conductivity. This phenomenon also appears in a prototype integrable quantum system of impenetrable particles, representing a strong-coupling limit of both models. In the thermodynamic limit, the two results could converge to a finite dc conductivity rather than an ideal conductor or insulator scenario.
We investigate the high-temperature dynamical conductivity σ(ω)\sigma(\omega)σ(ω) in two one-dimensional integrable quantum lattice models: the anisotropic XXZ spin chain and the Hubbard chain. The emphasis is on the metallic regime of both models, where besides the ballistic component, the regular part of conductivity might reveal a diffusive-like transport. To resolve the low-frequency dynamics, we upgrade the microcanonical Lanczos method enabling studies of finite-size systems with up to L≤32L\leq 32L≤32 sites for XXZ spin model with the frequency resolution δω∼10−3J\delta \omega \sim 10^{-3} Jδω∼10−3J. Results for the XXZ chain reveal a fine structure of σ(ω)\sigma(\omega)σ(ω) spectra, which originates from the discontinuous variation of the stiffness, previously found at commensurate values of the anisotropy parameter Δ\DeltaΔ. Still, we do not find a clear evidence for a diffusive component, at least not for commensurate values of Δ\DeltaΔ, particularly for Δ=0.5\Delta =0.5Δ=0.5, as well as for Δ→0\Delta \to 0Δ→0. Similar is the conclusion for the Hubbard model away from half-filling, where the spectra reveal more universal behavior.
We investigate the high-temperature dynamical conductivity $\ensuremath{\sigma}(\ensuremath{\omega})$ in two one-dimensional integrable quantum lattice models: the anisotropic XXZ spin chain and the Hubbard chain. The emphasis is on the metallic regime of both models, where besides the ballistic component, the regular part of conductivity might reveal a diffusivelike transport. To resolve the low-frequency dynamics, we upgrade the microcanonical Lanczos method enabling studies of finite-size systems with up to $L\ensuremath{\le}32$ sites for the XXZ spin model with the frequency resolution $\ensuremath{\delta}\ensuremath{\omega}\ensuremath{\sim}{10}^{\ensuremath{-}3}J$. Results for the XXZ chain reveal a fine structure of $\ensuremath{\sigma}(\ensuremath{\omega})$ spectra, which originates from the discontinuous variation of the stiffness, previously found at commensurate values of the anisotropy parameter $\mathrm{\ensuremath{\Delta}}$. Still, we do not find clear evidence for a diffusive component, at least not for commensurate values of $\mathrm{\ensuremath{\Delta}}$, particularly for $\mathrm{\ensuremath{\Delta}}=0.5$, as well as for $\mathrm{\ensuremath{\Delta}}\ensuremath{\rightarrow}0$. Similar is the conclusion for the Hubbard model away from half-filling, where the spectra reveal more universal behavior.
Using numerical diagonalization techniques we analyze the finite temperature/frequency conductance of a one-dimensional model of interacting spinless fermions. Depending on the interaction, the observed finite temperature charge stiffness and low-frequency conductance indicate a fundamental difference between integrable and nonintegrable cases. The integrable systems behave as ideal conductors in the metallic regime and as ideal insulators in the insulating one. The nonintegrable systems are, as expected, generic conductors in the metallic regime and activated ones in the insulating regime. \textcopyright{} 1996 The American Physical Society.
We study finite-temperature transport properties of the one-dimensional Hubbard model using the density matrix renormalization group. Our aim is twofold: First, we compute both the charge- and the spin-current correlation function of the integrable model at half filling. The former decays rapidly, implying that the corresponding Drude weight is either zero or very small. Second, we calculate the optical charge conductivity ${\ensuremath{\sigma}}_{r}eg(\ensuremath{\omega})$ in the presence of small integrability-breaking next-nearest-neighbor interactions (the extended Hubbard model). The dc conductivity is finite and diverges as the temperature is decreased below the gap. Our results thus suggest that the half-filled, gapped Hubbard model is a normal charge conductor at finite temperatures. As a test bed for our numerics, we compute ${\ensuremath{\sigma}}_{r}eg(\ensuremath{\omega})$ for the integrable XXZ spin chain in its gapped phase.
The dc conductivity for the t-J model is exactly obtained at t=J and for the Hubbard model in one dimension. Our calculation is carried out for arbitrary band filling by use of the finite-size-scaling method based on the Bethe-ansatz solution under twisted boundary conditions. The effective transport mass defined as the inverse of the conductivity serves as a sensitive probe of the metal-insulator transition. The effective mass is extremely enhanced near half-filling both for the t-J model at t=J and the repulsive Hubbard model, which is a direct evidence of the metal-insulator transition due to the electron correlation. We observe that the large antiferromagnetic coupling J in the t-J model increases the effective mass. On the other hand, the conductivity in the attractive Hubbard model exhibits quite different properties from the repulsive models.
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 nonintegrable 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 $\ensuremath{\eta}\ensuremath{\gtrsim}0.25$.