Strong Nernst-Ettingshausen effect in folded graphene

We study electronic transport in graphene under the influence of a transversal magnetic field $\f{B}(\f{r})=B(x)\f{e}_z$ with the asymptotics $B(x\to\pm\infty)=\pm B_0$, which could be realized via a folded graphene sheet in a constant magnetic field, for example. By solving the effective Dirac equation, we find robust modes with a finite energy gap which propagate along the fold -- where particles and holes move in opposite directions. Exciting these particle-hole pairs with incident photons would then generate a nearly perfect charge separation and thus a strong magneto-thermoelectric (Nernst-Ettingshausen) or magneto-photoelectric effect -- even at room temperature.