The two-particle propagator and magnetic susceptibility in the Hubbard model
The two-particle propagator and magnetic susceptibility in the Hubbard model
复制标题
哈伯德模型中的双粒子传播器和磁化率
DOI：
10.1088/0953-8984/17/19/007
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
R. Elliott
中科院分区：
文献类型：
--
作者：
A. Uldry;R. Elliott
我们使用最近发展的τ-CPA处理Hubbard模型中的两粒子绿色函数，该混合处理将相干势近似（CPA）应用到与带宽的倒数相关的时间τ，之后使用虚晶近似对系统进行平均。这个模型，与适当的近似，预测磁性的修改斯通纳标准。计算τ-CPA中的两粒子传播子需要求解纯CPA，在其形式体系中得到顶点校正和加权绿色函数。动力学磁化率，包括顶点校正和加权散射的剩余相互作用，计算和显示在铁磁制度的自旋波谱。
We treat the two-particle Green function in the Hubbard model using the recently developed τ-CPA, a hybrid treatment that applies the coherent potential approximation (CPA) up to a time τ related to the inverse of the bandwidth, after which the system is averaged using the virtual crystal approximation. This model, with suitable approximations, does predict magnetism for a modified Stoner criterion. The evaluation of the two-particle propagator in the τ-CPA requires the solution of the pure CPA, within whose formalism the vertex correction and the weighted Green functions are obtained. The dynamical susceptibility, including the vertex correction and the weighted scattering by the residual interaction, is calculated and shows a spin wave spectrum in the ferromagnetic regime.