首页> 外文OA文献 >Exact results for the optical absorption of strongly correlated electrons in a half-filled Peierls-distorted chain
【2h】

Exact results for the optical absorption of strongly correlated electrons in a half-filled Peierls-distorted chain

机译:光学吸收的确切结果强烈相关   半填充peierls扭曲链中的电子

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

In this second of three articles on the optical absorption of electrons in ahalf-filled Peierls-distorted chain we present exact results for stronglycorrelated tight-binding electrons. In the limit of a strong on-siteinteraction $U$ we map the Hubbard model onto the Harris-Lange model which canbe solved exactly in one dimension in terms of spinless fermions for the chargeexcitations. The exact solution allows for an interpretation of the chargedynamics in terms of parallel Hubbard bands with a free-electron dispersion ofband-width $W$, separated by the Hubbard interaction $U$. The spin degrees offreedom enter the expressions for the optical absorption only via a momentumdependent but static ground state expectation value. The remaining spin problemcan be traced out exactly since the eigenstates of the Harris-Lange model arespin-degenerate. This corresponds to the Hubbard model at temperatures largecompared to the spin exchange energy. Explicit results are given for theoptical absorption in the presence of a lattice distortion $\delta$ and anearest-neighbor interaction $V$. We find that the optical absorption for $V=0$is dominated by a peak at $\omega=U$ and broad but weak absorption bands for $|\omega -U | \leq W$. For an appreciable nearest-neighbor interaction, $V>W/2$,almost all spectral weight is transferred to Simpson's exciton band which iseventually Peierls-split.
机译:在有关半充满的Peierls扭曲链中电子的光吸收的三篇文章的第二篇中,我们给出了与强相关的紧密结合电子的精确结果。在强大的现场互动$ U $的限制下,我们将Hubbard模型映射到Harris-Lange模型上,该模型可以用无旋转费米子精确地一维求解电荷激发。精确的解决方案允许以平行的哈伯德带解释电荷动力学,其中平行的哈伯德带具有自由电子的带宽为$ W $,由哈伯德相互作用$ U $隔开。自旋自由度仅通过依赖于动量但静态的基态期望值输入光吸收的表达式。由于Harris-Lange模型的本征态是自旋简并的,因此可以精确地找出剩余的自旋问题。这与在比自旋交换能量大的温度下的哈伯德模型相对应。给出了在晶格畸变$ \ delta和最近邻相互作用$ V $的情况下的光吸收的明确结果。我们发现$ V = 0 $的光吸收主要由$ \ omega = U $的峰和$ | \ omega -U |的宽而弱的吸收带决定。 \ leq W $。对于明显的近邻相互作用,$ V> W / 2 $,几乎所有频谱权重都转移到辛普森的激子带,最终被皮尔尔斯分裂。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号