| Autor: |
Kretinin, A., Yu, G. L., Jalil, R., Cao, Y., Withers, F., Mishchenko, A., Katsnelson, M. I., Novoselov, K. S., Geim, A. K., Guinea, F. |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Phys. Rev. B, vol. 88, 165427 (2013) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.88.165427 |
| Popis: |
The next-nearest neighbor hopping term t' determines a magnitude and, hence, importance of several phenomena in graphene, which include self-doping due to broken bonds and the Klein tunneling that in the presence of t' is no longer perfect. Theoretical estimates for t' vary widely whereas a few existing measurements by using polarization resolved magneto-spectroscopy have found surprisingly large t', close or even exceeding highest theoretical values. Here we report dedicated measurements of the density of states in graphene by using high-quality capacitance devices. The density of states exhibits a pronounced electron-hole asymmetry that increases linearly with energy. This behavior yields t' approx -0.30 eV +-15%, in agreement with the high end of theory estimates. We discuss the role of electron-electron interactions in determining t' and overview phenomena which can be influenced by such a large value of t'. |
| Databáze: |
arXiv |
| Externí odkaz: |
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