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" Grafeno : Prêmio Nobel em Física de 2010 e Perspectivas Tecnológicas “ Yakov Kopelevich

20/04/2011. " Grafeno : Prêmio Nobel em Física de 2010 e Perspectivas Tecnológicas “ Yakov Kopelevich Instituto de Física "Gleb Wataghin", UNICAMP.

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" Grafeno : Prêmio Nobel em Física de 2010 e Perspectivas Tecnológicas “ Yakov Kopelevich

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  1. 20/04/2011 "Grafeno : Prêmio Nobel em Física de 2010 e Perspectivas Tecnológicas“ Yakov Kopelevich Instituto de Física "Gleb Wataghin", UNICAMP

  2. Nobel Prize in Physics 2010 – GRAPHENE (Andrei Geim & Konstantin Novoselov). According to the Oficial Web Site of the Nobel Prize (Nobelprize.org) this Prize has been awarded for “groundbreaking experiments regarding the two-dimensional material graphene”.

  3. Carbon allotropes

  4. Why graphene ? What are the “groundbreaking experiments” regarding this material ?

  5. Has graphene been experimentally obtained first in 2004 ? Actually, prior observations of graphene date back to at least 1962. H. P. Boehm et al. Zeitschrift für Naturforschung B17, 150 (1962). (TEM)

  6. EXPERIMENTS on GRAPHENE: 1992 1997

  7. 2000 2001

  8. HOPG = Highly Oriented Pyrolitic Graphite FLG c-axis With AFM tip: Xuekun Lu, Minfeng Yu, Hui Huang and Rodney S Ruoff Nanotechnology , 1999

  9. A The crystal structure of graphite: layers of honeycomb lattices of carbon atoms d = B A The single-atom thick graphitic planeis called "graphene" Dirac-like cone spectrum: E(p) =  vp; v ~ t||a/ћ, v  106 m/s F Band structure of one graphitic layer K - Fermi point

  10. Quantum Hall Effect Klaus von Klitzing

  11. Quantum oscillations and/or Quantum Hall Effect (QHE) originate from Landau quantization ћc > kBT Lev Landau B = 0 c > 1 1908 - 1968 or c << 1 Energy spectra En = ћc(n + 1/2), c = eB/m*

  12. Quantum Hall Array Resistance Standards

  13. Quantum effects at room temperature !

  14. ?!  ~ 104 cm2/Vs <<  ~ 106 cm2/Vs (graphite)

  15. Room-Temperature Quantum Oscillations in Bulk Graphite: More Experimental Evidence for Dirac-like Spectrum HOPG En = ±(2evF2|n|B)1/2  ~ 106 cm2/Vs ! Y. Kopelevich and P. Esquinazi, Advanced Materials 19, 4559 (2007)

  16. Andre Geim, Nobel Lecture 2010

  17. Finding of the Quantum Hall Effect in Graphite Y. Kopelevich et al., PRL 90, 156402 (2003); PRB 68, 165408 (2003). c/basal 105

  18. The occurrence of QHE in graphite has been confirmed by others: QHE measured for 8 m thick HOPG sample at T = 0.3 K; K. S. Novoselov et al., cond-mat/0410631 QHE measured for a few-layer thick graphite sample at T = 3 K; K. S. Novoselov et al., Science’2004

  19. Y. Kopelevich et al., PRL 2003 FLG Novoselov et al., 2004

  20. Dirac fermions in graphene and bulk graphite

  21. Bulk graphite

  22. I. A. Luk’yanchuk and Y. K. , PRL 93, 166402 (2004); ibid. 97, 256801 (2006) o – max xx (n) x - min xx (n + 1/2); shifted by 1/2 to the left Massiveelectrons Quasi-2D Dirac holes

  23. Hence, before graphene has been measured, its fundamental properties have already been experimentally uncovered.

  24. In graphite ! Phys. Rev. Lett. 103, 136403 (2009) Cyclotron resonance measurements on natural graphite

  25. spintronics

  26. One example: EPFL

  27. “Future of graphene”:

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