Orbital currents and charge density waves in a generalized Hubbard ladder
Abstract
We study a generalized Hubbard model on the twoleg ladder at zero temperature, focusing on a parameter region with staggered flux (SF)/ddensity wave (DDW) order. To guide our numerical calculations, we first investigate the location of a SF/DDW phase in the phase diagram of the halffilled weakly interacting ladder using a perturbative renormalization group (RG) and bosonization approach. For hole doping {delta} away from halffilling, finitesystem densitymatrix renormalizationgroup (DMRG) calculations are used to study ladders with up to 200 rungs for intermediatestrength interactions. In the doped SF/DDW phase, the staggered rung current and the rung electron density both show periodic spatial oscillations, with characteristic wavelengths 2/{delta} and 1/{delta}, respectively, corresponding to ordering wavevectors 2k {sub F} and 4k {sub F} for the currents and densities, where 2k {sub F} = {pi} (1  {delta}). The density minima are located at the antiphase domain walls of the staggered current. For sufficiently large dopings, SF/DDW order is suppressed. The rung density modulation also exists in neighboring phases where currents decay exponentially. We show that most of the DMRG results can be qualitatively understood from weakcoupling RG/bosonization arguments. However, while these arguments seem to suggest a crossover from nondecaying correlations to powerlaw decaymore »
 Authors:
 Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States) and Department of Physics, University of Queensland, Brisbane, Qld 4072 (Australia). Email: fjaerestad@physics.uq.edu.au
 Department of Physics, Brown University, Providence, RI 02912 (United States)
 Institute for Theoretical Physics C, RWTH Aachen, D52056 Aachen (Germany)
 Publication Date:
 OSTI Identifier:
 20767003
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Annals of Physics (New York); Journal Volume: 321; Journal Issue: 4; Other Information: DOI: 10.1016/j.aop.2005.08.005; PII: S00034916(05)001375; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BOSON EXPANSION; CHARGE DENSITY; CORRELATIONS; DENSITY MATRIX; ELECTRON DENSITY; FOCUSING; HOLES; HUBBARD MODEL; INTERACTIONS; MODULATION; OSCILLATIONS; PERIODICITY; PHASE DIAGRAMS; RENORMALIZATION; WAVELENGTHS
Citation Formats
Fjaerestad, J.O., Marston, J.B., and Schollwoeck, U.. Orbital currents and charge density waves in a generalized Hubbard ladder. United States: N. p., 2006.
Web. doi:10.1016/j.aop.2005.08.005.
Fjaerestad, J.O., Marston, J.B., & Schollwoeck, U.. Orbital currents and charge density waves in a generalized Hubbard ladder. United States. doi:10.1016/j.aop.2005.08.005.
Fjaerestad, J.O., Marston, J.B., and Schollwoeck, U.. Sat .
"Orbital currents and charge density waves in a generalized Hubbard ladder". United States.
doi:10.1016/j.aop.2005.08.005.
@article{osti_20767003,
title = {Orbital currents and charge density waves in a generalized Hubbard ladder},
author = {Fjaerestad, J.O. and Marston, J.B. and Schollwoeck, U.},
abstractNote = {We study a generalized Hubbard model on the twoleg ladder at zero temperature, focusing on a parameter region with staggered flux (SF)/ddensity wave (DDW) order. To guide our numerical calculations, we first investigate the location of a SF/DDW phase in the phase diagram of the halffilled weakly interacting ladder using a perturbative renormalization group (RG) and bosonization approach. For hole doping {delta} away from halffilling, finitesystem densitymatrix renormalizationgroup (DMRG) calculations are used to study ladders with up to 200 rungs for intermediatestrength interactions. In the doped SF/DDW phase, the staggered rung current and the rung electron density both show periodic spatial oscillations, with characteristic wavelengths 2/{delta} and 1/{delta}, respectively, corresponding to ordering wavevectors 2k {sub F} and 4k {sub F} for the currents and densities, where 2k {sub F} = {pi} (1  {delta}). The density minima are located at the antiphase domain walls of the staggered current. For sufficiently large dopings, SF/DDW order is suppressed. The rung density modulation also exists in neighboring phases where currents decay exponentially. We show that most of the DMRG results can be qualitatively understood from weakcoupling RG/bosonization arguments. However, while these arguments seem to suggest a crossover from nondecaying correlations to powerlaw decay at a length scale of order 1/{delta}, the DMRG results are consistent with a true longrange order scenario for the currents and densities.},
doi = {10.1016/j.aop.2005.08.005},
journal = {Annals of Physics (New York)},
number = 4,
volume = 321,
place = {United States},
year = {Sat Apr 15 00:00:00 EDT 2006},
month = {Sat Apr 15 00:00:00 EDT 2006}
}

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