skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: t-J{sub z} ladder: Density-matrix renormalization group and series expansion calculations of the phase diagram

Abstract

The phase diagram of the two-leg t-J{sub z} ladder is explored, using the density-matrix renormalization group method. Results are obtained for energy gaps, electron density profiles, and correlation functions for the half filled and quarter filled cases. The effective Lagrangian velocity parameter v{sub {rho}} is shown to vanish at half filling. The behavior of the one-hole gap in the Nagaoka limit is investigated, and found to disagree with theoretical predictions. A tentative phase diagram is presented, which is quite similar to the full t-J ladder, but scaled up by a factor of about 2 in coupling. Near half filling a Luther-Emery phase is found, which may be expected to show superconducting correlations, while near quarter filling the system appears to be in a Tomonaga-Luttinger phase.

Authors:
; ; ;  [1]
  1. School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia)
Publication Date:
OSTI Identifier:
20788061
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 73; Journal Issue: 14; Other Information: DOI: 10.1103/PhysRevB.73.144508; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CORRELATION FUNCTIONS; CORRELATIONS; COUPLING; DENSITY MATRIX; ELECTRON DENSITY; ENERGY GAP; HOLES; LAGRANGIAN FUNCTION; MATHEMATICAL MODELS; PHASE DIAGRAMS; RENORMALIZATION; SERIES EXPANSION; VELOCITY

Citation Formats

Weisse, A., Bursill, R. J., Hamer, C. J., and Weihong, Zheng. t-J{sub z} ladder: Density-matrix renormalization group and series expansion calculations of the phase diagram. United States: N. p., 2006. Web. doi:10.1103/PHYSREVB.73.1.
Weisse, A., Bursill, R. J., Hamer, C. J., & Weihong, Zheng. t-J{sub z} ladder: Density-matrix renormalization group and series expansion calculations of the phase diagram. United States. doi:10.1103/PHYSREVB.73.1.
Weisse, A., Bursill, R. J., Hamer, C. J., and Weihong, Zheng. Sat . "t-J{sub z} ladder: Density-matrix renormalization group and series expansion calculations of the phase diagram". United States. doi:10.1103/PHYSREVB.73.1.
@article{osti_20788061,
title = {t-J{sub z} ladder: Density-matrix renormalization group and series expansion calculations of the phase diagram},
author = {Weisse, A. and Bursill, R. J. and Hamer, C. J. and Weihong, Zheng},
abstractNote = {The phase diagram of the two-leg t-J{sub z} ladder is explored, using the density-matrix renormalization group method. Results are obtained for energy gaps, electron density profiles, and correlation functions for the half filled and quarter filled cases. The effective Lagrangian velocity parameter v{sub {rho}} is shown to vanish at half filling. The behavior of the one-hole gap in the Nagaoka limit is investigated, and found to disagree with theoretical predictions. A tentative phase diagram is presented, which is quite similar to the full t-J ladder, but scaled up by a factor of about 2 in coupling. Near half filling a Luther-Emery phase is found, which may be expected to show superconducting correlations, while near quarter filling the system appears to be in a Tomonaga-Luttinger phase.},
doi = {10.1103/PHYSREVB.73.1},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 14,
volume = 73,
place = {United States},
year = {Sat Apr 01 00:00:00 EST 2006},
month = {Sat Apr 01 00:00:00 EST 2006}
}
  • We consider repulsively interacting, cold fermionic atoms loaded on an optical ladder lattice in a trapping potential. The density-matrix renormalization-group method is used to numerically calculate the ground state for systematically varied values of interaction U and spin imbalance p in the Hubbard model on the ladder. The system exhibits rich structures, where a fully spin-polarized phase, spatially separated from other domains in the trapping potential, appears for large enough U and p. The phase-separated ferromagnetism can be captured as a real-space image of the energy gap between the ferromagnetic and other states arising from the combined effect of themore » Nagaoka ferromagnetism extended to the ladder and the density dependence of the energy separation between competing states. We also predict how to maximize the ferromagnetic region.« less
  • The ground-state phase diagram of 2D electrons in a high Landau level (index N=2 ) is studied by the density-matrix renormalization group method. Pair correlation functions are systematically calculated for various filling factors from {nu}=1/8 to 1/2 . It is shown that the ground-state phase diagram consists of three different charge density wave states called stripe phase, bubble phase, and Wigner crystal. The boundary between the stripe and the bubble phases is determined to be {nu}{sup s-b}{sub c}{similar_to}0.38 , and that for the bubble phase and Wigner crystal is {nu}{sup b-W}{sub c}{similar_to}0.24 . Each transition is of first order.
  • Using both the density-matrix renormalization group method and the constrained-path quantum Monte Carlo method, we studied the ground-state energies and the spin and hole densities of a 12x3 Hubbard model with open boundary conditions and six holes doped away from half-filling. Results obtained with these two methods agree well in the small and intermediate U regimes. For U/t{>=}6 we find a ground-state with charge inhomogeneities consistent with stripes. (c) 2000 The American Physical Society.
  • The recent discovery of superconductivity under high pressure in the two-leg ladder compound BaFe 2S 3 [H. Takahashi et al., Nat. Mater. 14, 1008 (2015)] opens a broad avenue of research, because it represents the first report of pairing tendencies in a quasi-one-dimensional iron-based high-critical-temperature superconductor. Similarly, as in the case of the cuprates, ladders and chains can be far more accurately studied using many-body techniques and model Hamiltonians than their layered counterparts, particularly if several orbitals are active. In this publication, we derive a two-orbital Hubbard model from first principles that describes individual ladders of BaFe 2S 3. Themore » model is studied with the density matrix renormalization group. These first reported results are exciting for two reasons: (i) at half-filling, ferromagnetic order emerges as the dominant magnetic pattern along the rungs of the ladder, and antiferromagnetic order along the legs, in excellent agreement with neutron experiments; and (ii) with hole doping, pairs form in the strong coupling regime, as found by studying the binding energy of two holes doped on the half-filled system. In addition, orbital selective Mott phase characteristics develop with doping, with only oneWannier orbital receiving the hole carriers while the other remains half-filled. Lastly, these results suggest that the analysis of models for iron-based two-leg ladders could clarify the origin of pairing tendencies and other exotic properties of iron-based high-critical-temperature superconductors in general.« less