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Title: Spin gaps in coupled [ital t]-[ital J] ladders

Abstract

Spin gaps in coupled [ital t]-[ital J] ladders are investigated by exact diagonalization of small clusters up to 4[times]8 sites. At half-filling, the numerical results for the triplet excitation spectrum are in very good agreement with a second-order perturbation expansion in terms of small interladder and intraladder exchange couplings between rungs ([ital J]/[ital J][prime][lt]0.25). The band of local triplet excitations moving coherently along the ladder (with momenta close to [pi]) is split by the interladder coupling. For intermediate couplings, finite-size scaling is used to estimate the spin gap. In the isotropic infinite four-chain system (two coupled ladders) we find a spin gap of 0.245[ital J], roughly half of the single-ladder spin gap. When the system is hole doped, bonding and antibonding bound pairs of holes can propagate coherently along the chains and the spin gap remains finite.

Authors:
 [1];  [2];  [3]
  1. Laboratoire de Physique Quantique, Universite Paul Sabatier, 31062 Toulouse (France)
  2. Theoretische Physik, ETH-Hoenggerberg, 8093 Zuerich (Switzerland) and Interdisziplinaeres Projektzentrum fuer Supercomputing, ETH-Zentrum, 8092 Zuerich (Switzerland)
  3. Theoretische Physik, ETH-Hoenggerberg, 8093 Zuerich (Switzerland)
Publication Date:
OSTI Identifier:
7071429
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter; (United States)
Additional Journal Information:
Journal Volume: 50:9; Journal ID: ISSN 0163-1829
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANTIFERROMAGNETIC MATERIALS; ELECTRON CORRELATION; HAMILTONIANS; HIGH-TC SUPERCONDUCTORS; CHAINS; CRYSTAL DOPING; EXCHANGE INTERACTIONS; EXCITATION; HEISENBERG MODEL; HOLES; HUBBARD MODEL; SCALING LAWS; TRIPLETS; CORRELATIONS; CRYSTAL MODELS; ENERGY-LEVEL TRANSITIONS; INTERACTIONS; MAGNETIC MATERIALS; MATERIALS; MATHEMATICAL MODELS; MATHEMATICAL OPERATORS; MULTIPLETS; QUANTUM OPERATORS; SUPERCONDUCTORS; 665411* - Basic Superconductivity Studies- (1992-)

Citation Formats

Poilblanc, D, Tsunetsugu, H, and Rice, T M. Spin gaps in coupled [ital t]-[ital J] ladders. United States: N. p., 1994. Web. doi:10.1103/PhysRevB.50.6511.
Poilblanc, D, Tsunetsugu, H, & Rice, T M. Spin gaps in coupled [ital t]-[ital J] ladders. United States. https://doi.org/10.1103/PhysRevB.50.6511
Poilblanc, D, Tsunetsugu, H, and Rice, T M. Thu . "Spin gaps in coupled [ital t]-[ital J] ladders". United States. https://doi.org/10.1103/PhysRevB.50.6511.
@article{osti_7071429,
title = {Spin gaps in coupled [ital t]-[ital J] ladders},
author = {Poilblanc, D and Tsunetsugu, H and Rice, T M},
abstractNote = {Spin gaps in coupled [ital t]-[ital J] ladders are investigated by exact diagonalization of small clusters up to 4[times]8 sites. At half-filling, the numerical results for the triplet excitation spectrum are in very good agreement with a second-order perturbation expansion in terms of small interladder and intraladder exchange couplings between rungs ([ital J]/[ital J][prime][lt]0.25). The band of local triplet excitations moving coherently along the ladder (with momenta close to [pi]) is split by the interladder coupling. For intermediate couplings, finite-size scaling is used to estimate the spin gap. In the isotropic infinite four-chain system (two coupled ladders) we find a spin gap of 0.245[ital J], roughly half of the single-ladder spin gap. When the system is hole doped, bonding and antibonding bound pairs of holes can propagate coherently along the chains and the spin gap remains finite.},
doi = {10.1103/PhysRevB.50.6511},
url = {https://www.osti.gov/biblio/7071429}, journal = {Physical Review, B: Condensed Matter; (United States)},
issn = {0163-1829},
number = ,
volume = 50:9,
place = {United States},
year = {1994},
month = {9}
}