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arXiv 0906.1233cond-mat.str-elcond-mat.dis-nn
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无序条件下的Holstein极化子

Holstein polaron in the presence of disorder

Mona Berciu, Andrei S. Mishchenko, Naoto Nagaosa

摘要:

通过引入非均匀动量平均(IMA)方法,再现了在实验中观察到的非局域、非均匀和延迟响应,研究了具有在位势无序和/或电子-声子耦合和/或声子频率空间变化的单极化子问题.我们表明,电子-声子耦合引起一个额外的不均匀,强烈推迟的潜力,这使得即时近似值得怀疑。IMA的准确性证明了从近似自由的图解蒙特卡罗(DMC)方法的结果进行比较。它的简单性使许多以前无法解决的问题变得容易研究。作为一个例子,我们展示了电子-声子耦合的不均匀性如何导致扫描隧道显微镜(STM)图像中的非局部延迟响应。

英文摘要:

Non-local, inhomogeneous and retarded response observed in experiments is reproduced by introducing the Inhomogeneous Momentum Average (IMA) method to study single polaron problems with disorder in the on-site potential and/or spatial variations of the electron-phonon couplings and/or phonon frequencies. We show that the electron-phonon coupling gives rise to an additional inhomogeneous, strongly retarded potential, which makes instant approximations questionable. The accuracy of IMA is demonstrated by comparison with results from the approximation free Diagrammatic Monte Carlo (DMC) method. Its simplicity allows for easy study of many problems that were previously unaccessible. As an example, we show how inhomogeneities in the electron-phonon coupling lead to nonlocal, retarded response in scanning tunneling microscopy (STM) images.

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。

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