论文标题
相互作用的各向异性电子气体中裸露椭圆度的Fermi-Surface拓扑和重新归一化
Fermi-surface topology and renormalization of bare ellipticity in an interacting anisotropic electron gas
论文作者
论文摘要
我们使用“ RPA-GW”自能量近似来研究电子 - 电子相互作用对费米表面形状的影响。我们发现，相互作用的费米表面与椭圆偏离，但并非以任意方式偏离。对于大多数$ r_s $的大多数值，相互作用的费米表面只有两个定性不同的形状。随着$ r_s $的增加，费米表面在这两种形状之间进行了两个不同的过渡。对于较大的$ r_s $，偏离椭圆的偏差程度会迅速增加，但通常，我们的理论即使对于相互作用的系统，我们的理论也为广泛使用的椭圆形费米表面近似值提供了理由，因为非椭圆形校正在数量上很小，但对于非常大的$ R_S $。
We investigate effects of electron-electron interactions on the shape of the Fermi surface in an anisotropic two-dimensional electron gas using the `RPA-GW' self-energy approximation. We find that the interacting Fermi surface deviates from an ellipse, but not in an arbitrary way. The interacting Fermi surface has only two qualitatively distinct shapes for most values of $r_s$. The Fermi surface undergoes two distinct transitions between these two shapes as $r_s$ increases. For larger $r_s$, the degree of the deviation from an ellipse rapidly increases, but, in general, our theory provides a justification for the widely used elliptical Fermi surface approximation even for the interacting system since the non-elliptic corrections are quantitatively rather small except for very large $r_s$.
