QM2 - Quantum Matter and Materials | December 08, 16:00

Gauge fields and strain engineering in graphene

Mikhail Katsnelson

It is demonstrated now both experimentally and theoretically that graphene is usually not flat but covered by ripples resulting from both intrinsic flexural instability of two-dimensional membranes and roughness of substrate. Thus charge carriers are not just Dirac fermions but Dirac fermions moving in a curved space. The effect of the corrugations on the electron spectrum can be described in terms of gauge (pseudo-magnetic) fields which result, in particular, in formation of pseudo-Landau levels predicted theoretically and found experimentally . These gauge fields can be used for "strain engineering", including tunable gap opening, quantum pumping [and creation of valley-polarized current. Ripples can induce puddles, that is, charge inhomogeneities. The scattering by the ripples is also one of the limiting factors restricting the charge carrier mobility in graphene.


University of Nijmegen
Seminar Room 0.03, ETP
Contact: George Marinescu