Report
Screening of Coulomb Impurities in Graphene
| العنوان: | Screening of Coulomb Impurities in Graphene |
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| المؤلفون: | Terekhov, Ivan S., Milstein, Alexander I., Kotov, Valeri N., Sushkov, Oleg P. |
| المصدر: | Physical Review Letters 100, 076803 (2008) |
| سنة النشر: | 2007 |
| المجموعة: | Condensed Matter Physics (Other) |
| مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science, Physics - Atomic Physics |
| الوصف: | We calculate exactly the vacuum polarization charge density in the field of a subcritical Coulomb impurity, $Z|e|/r$, in graphene. Our analysis is based on the exact electron Green's function, obtained by using the operator method, and leads to results that are exact in the parameter $Z\alpha$, where $\alpha$ is the "fine structure constant" of graphene. Taking into account also electron-electron interactions in the Hartree approximation, we solve the problem self-consistently in the subcritical regime, where the impurity has an effective charge $Z_{eff}$, determined by the localized induced charge. We find that an impurity with bare charge Z=1 remains subcritical, $Z_{eff} \alpha < 1/2$, for any $\alpha$, while impurities with $Z=2,3$ and higher can become supercritical at certain values of $\alpha$. Comment: 4 pages, 2 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevLett.100.076803 |
| URL الوصول: | http://arxiv.org/abs/0708.4263 |
| رقم الانضمام: | edsarx.0708.4263 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevLett.100.076803 |
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