Quantum Hall Effect in graphene
QHE has been demonstrated in graphene and the comparaison with QHE in GaAs settle the universality of QHE. The Klitzing constant is now chosen to define the unit of resistance namely the ohm. Although a metrological incertitude of 10-9 as already been obtained with GaAs, graphene allows to loosen the magnetic field and temperature constraints required with the GaAs system. A portable apparatus can be realized.
In collaboration with LNE with have already demonstrated the metrological value of the Klitzing constante in graphene Hall bar. In the framework of an ANR grant (LNE, Neel, Coulomb, C2N) we are working on a all graphene chip including a Hall bar and an electron pump for the current definition.