Tuesday, May 8, 2012

1205.1169 (Yichen Chang et al.)

Strain-Induced Quantum Hall States in Graphene    [PDF]

Yichen Chang, Tameem Albash, Stephan Haas
We examine strain-induced quantized Landau levels in graphene. Specifically, arc-bend strains are found to cause non-uniform pseudo-magnetic fields. Using an effective Dirac model which describes the low-energy physics around the nodal points, we show that several of the key qualitative properties of graphene in a strain-induced pseudo-magnetic field are different compared to the case of an externally applied physical magnetic field. We discuss how using different strain strengths allows us to spatially separate the two components of the pseudo-spinor on the different sublattices of graphene. These field theory results are checked against a tight-binding calculation on the graphene honeycomb lattice, which is found to exhibit all the features described. Furthermore, we find that introducing a Hubbard repulsion on the mean-field level induces a measurable polarization difference between the A and B sublattices, which provides an independent experimental test of the theory presented here.
View original: http://arxiv.org/abs/1205.1169

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