Excitations and finite-size properties of an integrable supersymmetric electronic model
Excitations and finite-size properties of an integrable supersymmetric electronic model
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DOI：
10.1103/physrevb.81.035120
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发表时间：
2009-10
影响因子：
3.7
通讯作者：
A. Malvezzi;M. J. Martins
中科院分区：
文献类型：
--
作者：
A. Malvezzi;M. J. Martins
我们研究了带有自由参数的Hubbard模型的一个可积推广的物理性质，它与超代数$sl(2|2)^{(2)}$的量子形变有关。Bethe ansatz解被用来确定自旋和电荷激发的性质。电荷分支的色散关系是由呈现无质量和质量行为的能量动量函数之间的特殊乘积给出的。对谱的有限尺寸修正的研究表明，基本的共形理论具有中心电荷$c=-1$和依赖于参数$\γ$的临界指数。我们注意到，在各向同性点$\Gamma=0$处可以建立精确的结果，而无需求助于Bethe ansatz解。
We investigate the physical properties of an integrable extension of the Hubbard model with a free parameter $\gamma$ related to the quantum deformation of the superalgebra $sl(2|2)^{(2)}$. The Bethe ansatz solution is used to determine the nature of the spin and charge excitations. The dispersion relation of the charge branch is given by a peculiar product between energy-momenta functions exhibiting massless and massive behaviors. The study of the finite-size corrections to the spectrum reveals us that the underlying conformal theory has central charge $c=-1$ and critical exponents depending on the parameter $\gamma$. We note that exact results at the isotropic point $\gamma=0$ can be established without recourse to the Bethe ansatz solution.