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arXiv 1407.4872cond-mat.str-el
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洪德定则耦合在激子密度波态中的作用

Roles of Hund's rule coupling in excitonic density-wave states

Tatsuya Kaneko, Yukinori Ohta

AI总结:

本研究基于含洪德定则耦合与对跳跃项的两带Hubbard模型,结合变分团簇近似计算,揭示了洪德定则耦合对激子自旋/电荷密度波态的相反调控作用及对跳跃项的增强效应,为相关材料研究提供了理论依据。

摘要:

本文在包含洪德定则耦合与对跳跃项的两带Hubbard模型中,研究了由电子-空穴对(即激子)量子凝聚实现的激子密度波态。利用变分团簇近似,我们计算了系统的巨势,并证明洪德定则耦合始终能稳定激子自旋密度波态、 destabilize激子电荷密度波态,且对跳跃项会增强这些效应。我们通过计算得到的单粒子谱函数、态密度、凝聚振幅以及对相干长度,讨论了这些激子密度波态的特征,同时还探讨了研究结果在材料层面的启示。

英文摘要:

Excitonic density-wave states realized by the quantum condensation of electron-hole pairs (or excitons) are studied in the two-band Hubbard model with Hund's rule coupling and the pair hopping term. Using the variational cluster approximation, we calculate the grand potential of the system and demonstrate that Hund's rule coupling always stabilizes the excitonic spin-density-wave state and destabilizes the excitonic charge-density-wave state and that the pair hopping term enhances these effects. The characteristics of these excitonic density-wave states are discussed using the calculated single-particle spectral function, density of states, condensation amplitude, and pair coherence length. Implications of our results in the materials' aspects are also discussed.

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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