Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2009-04-24
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
8 pages, 2 figures
Scientific paper
When smooth, zero-on-average, periodic magnetic and electric fields are applied to a carbon mono-layer (graphene), a gap between the valence and conduction band is introduced. Here this gapped state is studied analytically. It is found that it does not correspond to a band insulator: a constant electric field induces a quantized Hall current even though the magnetic flux through the sample is zero and there are no Landau levels. The phenomenon is of the same type as that discovered by Haldane for a graphene sample in a periodic magnetic field that is not smooth, i.e. varies rapidly on the scale of the graphene lattice constant. The effect can be explained in terms of the topological theory of Thouless, Kohmoto, Nightingale and den Nijs. For the system studied in this paper, an explanation in terms of simple physical principles is also presented. Thus some of the mystery is taken out of the apparently strange phenomenon of a Hall effect without magnetic flux. Furthermore, Haldane's model requires control over external magnetic fields on length scales less than an angstrom and is therefore hard to realize experimentally. For the model studied here, control over external fields on length scales that are larger by two orders of magnitude or more is sufficient. The model is therefore more amenable to experimental realization.
No associations
LandOfFree
The gapped state of a carbon mono-layer in periodic magnetic and electric fields does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The gapped state of a carbon mono-layer in periodic magnetic and electric fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The gapped state of a carbon mono-layer in periodic magnetic and electric fields will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-609775