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/0305610 · Physical review. B, Condensed matter

Anomalous behavior of the charge and spin degrees of freedom in the CuO double chains of PrBa2Cu4O8

Satoshi Nishimoto, Y. Ohta

Published Dec 24, 2003• 16 citations
arXivHTMLPDF

Abstract

The density-matrix renormalization-group method is used to study the electronic states of a two-chain Hubbard model for CuO double chains of ${\mathrm{PrBa}}_{2}{\mathrm{Cu}}_{4}{\mathrm{O}}_{8}.$ We show that the model at quarter filling has charge-ordered phases with stripe-type and in-line--type patterns in the parameter space, and in between, there appears a wide region of vanishing charge gap; the latter phase is characteristic of either a Tomonaga-Luttinger liquid or a metallic state with a spin gap. We argue that the low-energy electronic state of the CuO double chains of ${\mathrm{PrBa}}_{2}{\mathrm{Cu}}_{4}{\mathrm{O}}_{8}$ should be in the metallic state with a possibly small spin gap.

DOI
10.1103/physrevb.68.235114

Related papers

Superconductivity and Spin Gap in the Zigzag-Chaint–JModel Simulating a CuO Double Chain in Pr2Ba4Cu7O15-δ

Kazuhiro Sano, Yoshiaki Ōno

Using the numerical diagonalization method, we examine the one-dimensional t1–t2–J1–J2 model (zigzag-chain t–J model) which is an effective model for metallic CuO double chains in the superconductor Pr2Ba4Cu7O15-δ. Based on the Tomonaga–Luttinger liquid theory, we calculate the Luttinger liquid parameter Kρ as a function of the electron density n. It is found that superconductivity is realized in the parameter region, which is in accordance with experimental results. We show the phase diagram of a spin gap in the t2/|t1|–n plane by analyzing the expectation value of the twist operator Zσ in the spin sector. The spin gap appears in the region with a large t2/|t1|, where the phase boundary at half filling is consistent with that of the known frustrated quantum spin system. The analysis also suggests that the estimated value of the spin gap reaches ∼100 K in the realistic parameter region of Pr2Ba4Cu7O15-δ.

Journal of the Physical Society of Japan•Oct 24, 2007•6 citations

Superconductivity and Spin gap in the zigzag chain t-J model simulating a CuO double chain in Pr_2Ba_4Cu_7O_15-delta

azuhiro Sano, Yoshiaki Ōno

Using the numerical diagonalization method, we examine the one-dimensional t_1-t_2-J_1-J_2 model (zigzag chain t-J model) which represents an effective model for metallic CuO double chain in the superconductor Pr_2Ba_4Cu_7O_15-δ. Based on the Tomonaga-Luttinger liquid theory, we calculate the Luttinger-liquid parameter K_ρas a function of electron density n. It is found that superconductivity is realized in parameter region corresponding to the experimental result. We show phase diagram of spin gap on the t_2/|t_1|-n plane by analyzing the expectation value of twist-operator Z_σin the spin sector. The spin gap appears in the region with large t_2/|t_1|, where the phase boundary at half-filling is consistent with that of the known frustrated quantum spin system. The analysis also suggests that the estimated value of the spin gap reaches 100K in the realistic parameter region of Pr_2Ba_4Cu_7O_15-delta.

arXiv:0709.1206•Sep 8, 2007•0 citations

Tomonaga-Luttinger parameters and spin excitations in the dimerized extended Hubbard model

Satoshi Ejima, Florian Gebhard, Satoshi Nishimoto

We study the one-dimensional extended Hubbard model with alternating size of the hopping integrals using the density-matrix renormalization group method. We calculate the spin gap, the Tomonaga-Luttinger parameter, and the charge-density-wave order parameter for various dimerizations, interaction strengths, and band fillings. At half band-filling the spin and charge excitations are gapped but these gaps disappear for infinitesimal hole doping. At quarter filling, the umklapp scattering in the half-filled lower Peierls band generates a gap for the charge excitations but the gapless spin excitations can be described in terms of an effective antiferromagnetic Heisenberg model. Beyond a critical strength for the nearest-neighbor interaction, the dimerized extended Hubbard model at quarter filling develops a charge-density-wave ground state. The dimerization and the nearest-neighbor Coulomb interaction strongly reduce the Tomonaga-Luttinger parameter from its value for the bare Hubbard model. We discuss the relevance of our findings for the Bechgaard salts.

arXiv:cond-mat/0605433•Physical Review B•Dec 14, 2006•21 citations

The Doped Two-Chain Hubbard Model

R. M Noack, S. R White, Douglas J. Scalapino

The properties of the two-chain Hubbard model doped away from half-filling are investigated with the density matrix renormalization group. The charge gap is found to vanish, but a finite spin gap phase exists over a range of interchain hopping strength t ⊥ . In this phase, there are modified d x 2 - y 2 pairing correlations which exhibit a power law decay while both the 2 k F spin and charge correlations are short range. Above a critical value of t ⊥ , the system behaves as a Luttinger liquid.

arXiv:cond-mat/9409065•Europhysics Letters (EPL)•Apr 20, 1995•76 citations

Phase diagram of the quarter-filled extended Hubbard model on a two-leg ladder

Matthias Vojta C, A. Hübsch, R. M. Noack

We investigate the ground-state phase diagram of the quarter-filled Hubbard ladder with nearest-neighbor Coulomb repulsion $V$ using the density matrix renormalization-group technique. The ground state is homogeneous at small $V,$ a ``checkerboard'' charge-ordered insulator at large $V$ and not too small on site Coulomb repulsion U, and is phase separated for moderate or large $V$ and small U. The zero-temperature transition between the homogeneous and the charge-ordered phase is found to be second order. In both the homogeneous and the charge-ordered phases the existence of a spin gap mainly depends on the ratio of interchain to intrachain hopping. In the second part of the paper we construct an effective Hamiltonian for the spin degrees of freedom in the strong-coupling, charge-ordered regime that maps the system onto a frustrated spin chain. The opening of a spin gap is thus connected with spontaneous dimerization.

arXiv:cond-mat/0008068•Physical review. B, Condensed matter•Jan 8, 2001•51 citations

Phase diagram of the one-dimensional Hubbard model with next-nearest-neighbor hopping

Satoshi Nishimoto, Kazuhiro Sano, Y. Ohta

We study the one-dimensional Hubbard model with nearest-neighbor and next-nearest-neighbor hopping integrals by using the density-matrix renormalization group method and Hartree-Fock approximation. Based on the calculated results for the spin gap, total-spin quantum number, and Tomonaga-Luttinger-liquid parameter, we determine the ground-state phase diagram of the model in the entire filling and wide parameter region. We show that, in contrast to the weak-coupling regime where a spin-gapped liquid phase is predicted in the region with four Fermi points, the spin gap vanishes in a substantial region in the strong-coupling regime. It is remarkable that a large variety of phases, such as the paramagnetic metallic phase, spin-gapped liquid phase, singlet and triplet superconducting phases, and fully polarized ferromagnetic phase, appear in such a simple model in the strong-coupling regime.

arXiv:0710.2274•Physical Review B•Feb 26, 2008•21 citations
The density-matrix renormalization-group method is used to study the electronic states of a two-chain Hubbard model for CuO double chains of PrBa2Cu4O8.{\mathrm{PrBa}}_{2}{\mathrm{Cu}}_{4}{\mathrm{O}}_{8}.PrBa2​Cu4​O8​. We show that the model at quarter filling has charge-ordered phases with stripe-type and in-line--type patterns in the parameter space, and in between, there appears a wide region of vanishing charge gap; the latter phase is characteristic of either a Tomonaga-Luttinger liquid or a metallic state with a spin gap. We argue that the low-energy electronic state of the CuO double chains of PrBa2Cu4O8{\mathrm{PrBa}}_{2}{\mathrm{Cu}}_{4}{\mathrm{O}}_{8}PrBa2​Cu4​O8​ should be in the metallic state with a possibly small spin gap.
Using the numerical diagonalization method, we examine the one-dimensional t1–t2–J1–J2 model (zigzag-chain t–J model) which is an effective model for metallic CuO double chains in the superconductor Pr2Ba4Cu7O15-δ. Based on the Tomonaga–Luttinger liquid theory, we calculate the Luttinger liquid parameter Kρ as a function of the electron density n. It is found that superconductivity is realized in the parameter region, which is in accordance with experimental results. We show the phase diagram of a spin gap in the t2/|t1|–n plane by analyzing the expectation value of the twist operator Zσ in the spin sector. The spin gap appears in the region with a large t2/|t1|, where the phase boundary at half filling is consistent with that of the known frustrated quantum spin system. The analysis also suggests that the estimated value of the spin gap reaches ∼100 K in the realistic parameter region of Pr2Ba4Cu7O15-δ.
Using the numerical diagonalization method, we examine the one-dimensional t_1-t_2-J_1-J_2 model (zigzag chain t-J model) which represents an effective model for metallic CuO double chain in the superconductor Pr_2Ba_4Cu_7O_15-δ. Based on the Tomonaga-Luttinger liquid theory, we calculate the Luttinger-liquid parameter K_ρas a function of electron density n. It is found that superconductivity is realized in parameter region corresponding to the experimental result. We show phase diagram of spin gap on the t_2/|t_1|-n plane by analyzing the expectation value of twist-operator Z_σin the spin sector. The spin gap appears in the region with large t_2/|t_1|, where the phase boundary at half-filling is consistent with that of the known frustrated quantum spin system. The analysis also suggests that the estimated value of the spin gap reaches 100K in the realistic parameter region of Pr_2Ba_4Cu_7O_15-delta.
We study the one-dimensional extended Hubbard model with alternating size of the hopping integrals using the density-matrix renormalization group method. We calculate the spin gap, the Tomonaga-Luttinger parameter, and the charge-density-wave order parameter for various dimerizations, interaction strengths, and band fillings. At half band-filling the spin and charge excitations are gapped but these gaps disappear for infinitesimal hole doping. At quarter filling, the umklapp scattering in the half-filled lower Peierls band generates a gap for the charge excitations but the gapless spin excitations can be described in terms of an effective antiferromagnetic Heisenberg model. Beyond a critical strength for the nearest-neighbor interaction, the dimerized extended Hubbard model at quarter filling develops a charge-density-wave ground state. The dimerization and the nearest-neighbor Coulomb interaction strongly reduce the Tomonaga-Luttinger parameter from its value for the bare Hubbard model. We discuss the relevance of our findings for the Bechgaard salts.
The properties of the two-chain Hubbard model doped away from half-filling are investigated with the density matrix renormalization group. The charge gap is found to vanish, but a finite spin gap phase exists over a range of interchain hopping strength t ⊥ . In this phase, there are modified d x 2 - y 2 pairing correlations which exhibit a power law decay while both the 2 k F spin and charge correlations are short range. Above a critical value of t ⊥ , the system behaves as a Luttinger liquid.
We investigate the ground-state phase diagram of the quarter-filled Hubbard ladder with nearest-neighbor Coulomb repulsion VVV using the density matrix renormalization-group technique. The ground state is homogeneous at small V,V,V, a ``checkerboard'' charge-ordered insulator at large VVV and not too small on site Coulomb repulsion U, and is phase separated for moderate or large VVV and small U. The zero-temperature transition between the homogeneous and the charge-ordered phase is found to be second order. In both the homogeneous and the charge-ordered phases the existence of a spin gap mainly depends on the ratio of interchain to intrachain hopping. In the second part of the paper we construct an effective Hamiltonian for the spin degrees of freedom in the strong-coupling, charge-ordered regime that maps the system onto a frustrated spin chain. The opening of a spin gap is thus connected with spontaneous dimerization.
We study the one-dimensional Hubbard model with nearest-neighbor and next-nearest-neighbor hopping integrals by using the density-matrix renormalization group method and Hartree-Fock approximation. Based on the calculated results for the spin gap, total-spin quantum number, and Tomonaga-Luttinger-liquid parameter, we determine the ground-state phase diagram of the model in the entire filling and wide parameter region. We show that, in contrast to the weak-coupling regime where a spin-gapped liquid phase is predicted in the region with four Fermi points, the spin gap vanishes in a substantial region in the strong-coupling regime. It is remarkable that a large variety of phases, such as the paramagnetic metallic phase, spin-gapped liquid phase, singlet and triplet superconducting phases, and fully polarized ferromagnetic phase, appear in such a simple model in the strong-coupling regime.