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arXiv 2311.08064cond-mat.mes-hall
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石墨烯中的带电空位:朗道能级与原子坍缩共振的相互作用

Charged vacancy in graphene: interplay between Landau levels and atomic collapse resonances

Jing Wang, Wen-Sheng Zhao, Yue Hu, R. N. Costa Filho, Francois M. Peeters

AI总结:

本文通过紧束缚模型研究石墨烯中带电空位引起的库仑势与磁场的相互作用,发现卫星能级、原子坍缩共振及朗道能级交叉,并揭示临界电荷与磁场无关的标度异常。

摘要:

在紧束缚模型中研究了磁场与带电空位产生的库仑势对石墨烯电子态的相互作用。库仑势局部消除了朗道能级的简并性,而空位则在正常朗道能级旁边引入了一个卫星能级。这些卫星能级存在于正能区,但在负能区转变为原子坍缩共振。发现了具有不同角量子数$m$的朗道能级之间的交叉。与点杂质系统中相同$m$的朗道能级之间发生反交叉不同,本工作中发现正常朗道能级与空位诱导能级之间存在反交叉。原子坍缩共振与朗道能级发生杂化。最低朗道能级$m = -1, N = 1$交叉时的电荷随磁场增强而增加,并在$E = 0$处交叉。当电荷大于临界电荷$\beta\approx0.6$时,出现朗道能级标度异常,且该临界电荷与磁场无关。

英文摘要:

The interplay between a magnetic field and the Coulomb potential from a charged vacancy on the electron states in graphene is investigated within the tight-binding model. The Coulomb potential removes locally Landau level degeneracy, while the vacancy introduces a satellite level next to the normal Landau level. These satellite levels are found throughout the positive energy region, but in the negative energy region they turn into atomic collapse resonances. Crossings between Landau levels with different angular quantum number $m$ are found. Unlike the point impurity system in which an anticrossing occurs between Landau levels of the same $m$, in this work anticrossing is found between the normal Landau level and the vacancy induced level. The atomic collapse resonance hybridize with the Landau levels. The charge at which the lowest Landau level $m = -1, N = 1$ crosses increases $E = 0$ with enhancing magnetic field. Landau level scaling anomaly occurs when the charge is larger than the critical charge $β\approx0.6$ and this critical charge is independent of the magnetic field.

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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