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arXiv 1005.0930cond-mat.mtrl-scicond-mat.other
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六方氮化硼能量损失函数中的各向异性激子效应

Anisotropic excitonic effects in the energy loss function of hexagonal boron nitride

S. Galambosi, L. Wirtz, J. A. Soininen, J. Serrano, A. Marini, K. Watanabe, T. Taniguchi, S. Huotari, A. Rubio, K. Hämäläinen

摘要:

我们证明了六方氮化硼(hBN)的价能损失函数在形状、激发能和动量转移q的色散方面表现出很强的各向异性。这通过例如0.7eV的能量偏移来证明,该能量偏移不能通过单粒子方法来捕获,并且是两体电子-空穴相互作用中的强各向异性的证明。此外,对于面内方向的q,我们观察到分裂的-等离子体激元在M方向是不存在的K方向,这可以追溯到带结构的影响。

英文摘要:

We demonstrate that the valence energy-loss function of hexagonal boron nitride (hBN) displays a strong anisotropy in shape, excitation energy and dispersion for momentum transfer q parallel or perpendicular to the hBN layers. This is manifested by e.g. an energy shift of 0.7 eV that cannot be captured by single-particle approaches and is a demonstration of a strong anisotropy in the two-body electron-hole interaction. Furthermore, for in-plane directions of q we observe a splitting of the -plasmon in the M direction that is absent in the K direction and this can be traced back to band-structure effects.

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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