论文标题
库仑伪电势的起源
Origin of the Coulomb Pseudopotential
论文作者
论文摘要
我们解决了在库仑参数的较小至中度值，$ r_s \ sillsim 2 $的情况下存在强库仑排斥力的情况下的杰出问题，并证明了伪能力框架从根本上有偏见和不受控制。取而代之的是，必须将净结果分解为两个截然不同的效果：费米液体重新归一化因子和有效低能耦合的变化。后一个数量显示出非单调性的行为，其极值为$ r_s \约0.75 $。在随机相位近似中，库仑相互作用开始以$ r_s> 2 $增强有效的配对耦合，并且临界温度的抑制完全是由于重新归一化的费米液体性能。领先的顶点校正仅数量地更改此图片。我们的结果要求对广泛接受的排斥伪能力方法进行根本性的重新考虑，并表明需要精确的微观处理库仑相互作用，这是超导不稳定的问题。
We address the outstanding problem of electron pairing in the presence of strong Coulomb repulsion at small to moderate values of the Coulomb parameter, $r_s \lesssim 2$, and demonstrate that the pseudopotential framework is fundamentally biased and uncontrolled. Instead, one has to break the net result into two distinctively different effects: the Fermi liquid renormalization factor and the change in the effective low-energy coupling. The latter quantity is shown to behave non-monotonically with an extremum at $ r_s\approx 0.75$. Within the random-phase approximation, Coulomb interaction starts to enhance the effective pairing coupling at $r_s >2$, and the suppression of the critical temperature is entirely due to the renormalized Fermi liquid properties. Leading vertex corrections change this picture only quantitatively. Our results call for radical reconsideration of the widely accepted repulsive pseudopotential approach and show the need for precise microscopic treatment of Coulomb interactions in the problem of superconducting instability.
