拓扑转变附近的增强相互作用效应
Enhanced interaction effects in the vicinity of the topological transition
摘要：
拓扑转变附近的金属可以粗略地看作由两组电子组成。第一组是占据大部分布里渊区的“体”电子。第二组是波矢接近拓扑转变点的电子。第一组电子的动能$\tilde{E}_F$远大于第二组电子的动能$E_F$。由于第二组电子的速度较慢，这些电子的相互作用效应更加明显。我们进行了计算，说明第二组的电子是负责非弹性寿命，使其非常短，使准粒子的概念适用于这些电子只有边缘。我们还表明，相互作用重整化的光谱附近的拓扑转变的电子，重整化的光谱的参数强烈依赖于接近过渡。另一个随着费米能级扫过跃迁而急剧演化的多体效应是第二群电子在杂质周围产生的电子密度的弗里德尔振荡。这些振荡是强烈的各向异性与周期取决于方向。这些振荡的电子散射引起的温度依赖的弹道修正的电导率。
英文摘要：
A metal near the topological transition can be loosely viewed as consisting of two groups of electrons. First group are "bulk" electrons occupying most of the Brillouin zone. Second group are electrons with wave vectors close to the topological transition point. Kinetic energy, $\tilde{E}_F$, of electrons of the first group is much bigger than kinetic energy, $E_F$, of electrons of the second group. With electrons of the second group being slow, the interaction effects are more pronounced for these electrons. We perform a calculation illustrating that electrons of the second group are responsible for inelastic lifetime making it anomalously short, so that the concept of quasiparticles applies to these electrons only marginally. We also demonstrate that interactions renormalize the spectrum of electrons in the vicinity of topological transition, the parameters of renormalized spectrum being strongly dependent on the proximity to the transition. Another many-body effect that evolves dramatically as the Fermi level is swept through the transition is the Friedel oscillations of the electron density created by electrons of the second group around an impurity. These oscillations are strongly anisotropic with a period depending on the direction. Scattering of electrons off these oscillations give rise to a temperature-dependent ballistic correction to the conductivity.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
