Gauge-invariant response functions of fermions coupled to a gauge field.
Gauge-invariant response functions of fermions coupled to a gauge field.
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耦合到规范场的费米子的规范不变响应函数。
DOI：
10.1103/physrevb.50.17917
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
P. Lee
中科院分区：
文献类型：
--
作者：
Yong Baek Kim;A. Furusaki;X. Wen;P. Lee
我们研究了费米子与规范场相互作用的模型，并计算了规范不变的两粒子绿色函数或响应函数。的领导奇异贡献的自能校正被取消的顶点校正小$q$和$\欧米茄$。因此，剩余的贡献是不够奇异的，以改变随机相位近似的领先阶的结果。它还表明，规范场传播子是不重整化的两圈的顺序。我们检查由此产生的规范不变的两粒子绿色的功能小$q$和$\欧米茄$，但所有的比例$\欧米茄/ v_F q$，我们得出结论，它们可以描述费米液体形式没有发散的有效质量。
We study a model of fermions interacting with a gauge field and calculate gauge-invariant two-particle Green's functions or response functions. The leading singular contributions from the self-energy correction are found to be cancelled by those from the vertex correction for small $q$ and $\Omega$. As a result, the remaining contributions are not singular enough to change the leading order results of the random phase approximation. It is also shown that the gauge field propagator is not renormalized up to two-loop order. We examine the resulting gauge-invariant two-particle Green's functions for small $q$ and $\Omega$, but for all ratios of $\Omega / v_F q$ and we conclude that they can be described by Fermi liquid forms without a diverging effective mass.