Application of the renormalization group technique to the problem of phase transition in one-dimensional metallic systems. I. Invariant couplings, vertex, and one-particle Green's function
Application of the renormalization group technique to the problem of phase transition in one-dimensional metallic systems. I. Invariant couplings, vertex, and one-particle Green's function
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重正化群技术在一维金属体系相变问题中的应用。
DOI：
10.1007/bf00654955
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
J. Sólyom
中科院分区：
文献类型：
--
作者：
N. Menyhárd;J. Sólyom
用重整化群方法研究了一个通过BCS型相互作用的一维电子系统，在两个逐次近似ATT=0下，只保留了一个能量变量ω。一次近似等价于Bychkovet et al.的前导对数项的求和，相应地，顶点函数在有限值ω处表现出奇异性。第二个近似值也解释了下一个前导对数项，通过这种方法，奇点被下推到ω=0。然而，由于重要的自能贡献，不变耦合的行为不同，并且在ω=0时趋向于饱和值。
A one-dimensional system of electrons interacting via a BCS-type interaction is investigated by renormalization group techniques in two successive approximations atT=0, keeping only a single energy variable ω. The first approximation is equivalent to the summation of leading logarithmic terms carried out by Bychkovet al., and correspondingly the vertex function displays a singularity at a finite value of ω. The second approximation accounts for the next leading logarithmic terms as well, and by this means the singularity is shown to be pushed down to ω=0. Due to important self-energy contributions, however, the invariant couplings behave differently and tend to a saturation value at ω=0.