Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 93: Graphen (organized by DS)

TT 93.5: Vortrag

Donnerstag, 19. März 2015, 10:30–10:45, H 0111

Uniformity of the pseudo-magnetic field in strained graphene — •Gerard Verbiest, Sascha Brinker, and Christoph Stampfer — JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany

Graphene is a very promising candidate as active material in future electronic applications. However, its electrical properties are very sensitive to mechanical disturbances, as graphene is only one atomic layer thick. This coupling theoretically gives rise to a so-called "pseudo-vector field", and consequently to a "pseudo-magnetic field".

The pseudo-magnetic field can, just as a real magnetic field, induce Landau levels in graphene, if the field is strong enough. In order to utilize, i.e. measure this effect, one needs (i) a high sample quality and (ii) a large uniformity of the pseudo-magnetic field.

Here we present numerical simulations of the pseudo-magnetic field in graphene with a hexagonal shape as a function of tri-axial strain. We defined a radius of uniformity, as the radius for which the standard deviation from the pseudo-magnetic field in the center reaches 1%. For a hexagon with sides of 100 nm and a strain of 10%, the pseudo-magnetic field strength is ~40 T and is uniform within a diameter of 34 nm. For a hexagonal sample size with sides of 1 micron with a strain of 3.5%, the maximum pseudo-magnetic field is reduced to ~1.2 T, but it is uniform within a diameter of 540 nm.