共查询到20条相似文献,搜索用时 15 毫秒
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F. Pan M.-X. Xie J.-J. Lin X.-G. Xue J. P. Draayer 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,72(4):479-484
The one-dimensional t-J
model Hamiltonian is realized by using hard-core boson operators. A
simple algorithm written in Mathematica based on a differential
realization of the hard-core bosons for finding exact solutions of
the model is proposed. As a simple example, some low-lying
excitation energies, the inverse compressibility, and the
superconducting structure factors, as well as the particle and spin
entanglement of a system with 8 sites are calculated. The results
not only confirm the validity of the hard-core boson picture, but
also indicate that a quantum phase transition near phase-separation
at zero temperature can also be recognized by the particle and spin
entanglement. 相似文献
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We study the binding of a holon and a spinon in the one-dimensional anisotropic t-J model using a Bethe-Salpeter equation approach, exact diagonalization, and density matrix renormalization group methods on chains of up to 128 sites. We find that holon-spinon binding changes dramatically as a function of anisotropy parameter alpha=J( perpendicular)/J(z): it evolves from an exactly deducible impuritylike result in the Ising limit to an exponentially shallow bound state near the isotropic case. A remarkable agreement between the theory and numerical results suggests that such a change is controlled by the corresponding evolution of the spinon energy spectrum. 相似文献
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Hanqin Ding Yanshen Wang 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,79(2):169-175
Using the deformed Hubbard operator approach, we analytically study weak-coupling phase diagram of the one-dimensional t-J-V model at half filling. In the case of small deformed parameter ζ(≪1), the interactions induced by the no double occupancy constraint are softened, accessible by the bosonization field theory
and the renormalization group technique. The ground state exhibits insulating behavior of density-wave correlations. The bond-spin-density-wave
(BSDW) and
bond-charge-density-wave (BCDW) phases are realized in the whole weak-coupling regime while the charge-density-wave (CDW)
and spin-density-wave (SDW) phases depend on V/J > (V/J)
c
or V/J < (V/J)
c
, where (V/J)
c
= 1/4. Furthermore, our results are expected to adiabatically continue back to ζ = 1. 相似文献