Nernst-Ettingshausen effect in Bismuth across the quantum limit

In elemental Bismuth, 10$^{5}$ atoms share a single itinerant electron. A magnetic field of the order of 10 T can confine electrons to the lowest Landau level. We report on the first study of metallic thermoelectricity in this regime. The thermoelectric response is mainly off-diagonal and peaks each time a Landau level hits the chemical potential. The associated maxima in the Ettingshausen coefficient saturates to a temperature-independent magnitude offering a notable constraint for theory.