论文标题
与远程库仑相互作用的分层T-J模型中量子电荷波动的电子能源
Electron self-energy from quantum charge fluctuations in the layered t-J model with long-range Coulomb interaction
论文作者
论文摘要
通过远程库仑相互作用，采用层状T-J模型的大N方案，该模型捕获了最近在Cuprate超导体中观察到的电荷激发光谱的细节，我们探索了电荷波动在电子自我能源上的作用。我们将温度固定为零，并专注于量子电荷波动。我们发现，相对于$ω= 0 $，自我能源IM $σ（{\ bf k}，ω）的虚构部分的明显不对称部分，这是由强电子相关效应驱动的。准粒子的重量大大减轻，沿费米表面几乎各向同性。新生成并获得了相当大的光谱重量，因此同时产生了一个不连贯的带和锋利的侧带。所有这些特征都是由通常的现场电荷波动驱动的，这些波动在相当高的区域和产量等离子体激发的区域中实现。另一方面，具有巨大交互作用尺度的低能区域J由粘结式波动主导。令人惊讶的是，与现场电荷波动的效果相比，即使系统接近接近债券电荷不稳定性，它们对电子的影响也弱得多。此外，量子电荷动力学不会在电子分散体中产生清晰的扭结和伪群。
Employing a large-N scheme of the layered t-J model with the long-range Coulomb interaction, which captures fine details of the charge excitation spectra recently observed in cuprate superconductors, we explore the role of the charge fluctuations on the electron self-energy. We fix temperature at zero and focus on quantum charge fluctuations. We find a pronounced asymmetry of the imaginary part of the self-energy Im$Σ({\bf k}, ω)$ with respect to $ω= 0$, which is driven by strong electron correlation effects. The quasiparticle weight is reduced dramatically, which occurs almost isotropically along the Fermi surface. Concomitantly an incoherent band and a sharp side band are newly generated and acquire sizable spectral weight. All these features are driven by usual on-site charge fluctuations, which are realized in a rather high-energy region and yield plasmon excitations. On the other hand, the low-energy region with the scale of the superexchange interaction J is dominated by bond-charge fluctuations. Surprisingly, compared with the effect of the on-site charge fluctuations, their effect on the electron self-energy is much weaker even if the system approaches close to bond-charge instabilities. Furthermore, quantum charge dynamics does not produce a clear kink nor a pseudogap in the electron dispersion.
