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Physics Program presents

Effects of a Periodic Scatter Potential on the Landau Quantization and Ballistic Transport in Graphene

Thursday, November 14, 2013

[Effects of a Periodic Scatter Potential on the Landau Quantization and Ballistic Transport in Graphene]
A lecture by
Dr. Paula Fekete, Assistant Professor
Department of Physics and Nuclear Engineering
US Military Academy at West Point, NY

Graphene is a single atomic layer of carbon atoms bound in a hexagonal lattice. It was first produced experimentally in 2004 by a team of researchers from Manchester, UK, and Chernogolovka, Russia, through mechanical exfoliation. This event started the “graphene revolution,” which spread quickly around the world attracting the attention of scientists and engineers alike. Graphene’s discovery was awarded the Physics Nobel Prize in 2010 and the number of publications and patents related to it is still sharply increasing. This talk will give an overview of some of graphene’s surprising electrical and transport properties that arise due to its two-dimensional structure. Namely, graphene’s electrons, moving in the periodic lattice potential of the two-dimensional crystal, form energy bands. These band energies can be described by a wave equation in which the mass of electrons is effectively changed. In a strong magnetic field, the cyclotron orbits of electrons are quantized and Landau levels form. In 1976, Hofstadter showed that, for a two-dimensional electron system, the interplay between these two quantum effects can lead to a fractal-type energy spectrum known as “Hofstadter’s Butterfly.” The talk presents results that indicate that the Hofstadter Butterfly appears in graphene’s energy spectrum as well.

Location: Hegeman 107