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The continuum model for the twisted graphene bilayer

Prof. João Lopes dos Santos
Thu, 12/01/2012 - 12:00pm to 1:00pm
Physics Conference Room, S13 M01-11/12
Event Type: 


The electronic structure of the twisted bilayer was first considered in the context of a continuum description of the two layers, coupled by a spatially modulated hopping. The model's predictions were subsequently confirmed by several experiments, including a scanning tunneling spectroscopy finding of two low energy Van-Hove peaks in the density of states, and by band structure calculations.

We discuss the extension of the model in several directions:

the two families of commensurate structures discovered by Mele, will be characterized by elementary geometrical arguments; it will be shown that it is possible to calculate analytically all Fourier components of the hopping amplitudes for any kind of commensurate structure with large period; the calculations will be extended beyond the perturbative regime in the interlayer coupling to address the electronic structure and local density of states in the very small angle limit.


The Speaker


João Lopes dos Santos is an Associate Professor of Physics at the University of Porto. He obtained his Phd at Imperial College in London, in Theoretical Condensed Matter Physics. He was a post-doc at Rutgers University and a visiting scholar at Boston University on several occasions. He is currently focused on Research in graphene, especially on the bilayer and the effects of twisting between layers. He is currently the Head of the Physics and Astronomy Department of Porto University.

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