59 research outputs found
Persistent Hall Voltage and Current in the Fractional Quantum Hall Regime
The persistent Hall voltage and current in an isolated annulus in a strong
perpendicular magnetic field, at odd inverse filling factor, and in the
presence of a weak constriction is obtained as a function of temperature, and
flux piercing the annulus. A thermodynamic Hall conductance is found which has
a universal value even with back scattering at the constriction. Included are
detailed appendices on the bosonization of chiral soliton operators and the
derivation of the chiral action, which has an additional topological term
originating from the dynamics of the zero modes.Comment: 12 pages, Late
Quantum Corrections to Thermopower and Conductivity in Graphene
The quantum corrections to the conductivity and the thermopower in monolayer
graphene are studied. We use the recursive Green's function method to calculate
numerically the conductivity and the thermopower of graphene. We then analyze
these weak localization corrections by fitting with the analytical theory as
function of the impurity parameters and the gate potential. As a result of the
quantum corrections to the thermopower, we find large magnetothermopower which
is shown to provide a very sensitive measure of the size and strength of the
impurities. We compare these analytical and numerical results with existing
experimental measurements of magnetoconductance of single layer graphene and
find that the average size and strength of the impurities in these samples can
thereby be determined. We suggest favorable parameter ranges for future
measurements of the magnetothermopower
- …