  With a widely available magnetic field of 10 T, one can attain the quantum
limit in bismuth and graphite. At zero magnetic field, these two elemental
semi-metals host a dilute liquid of carriers of both signs. When the quantum
limit is attained, all quasi-particles are confined to a few Landau tubes. Each
time a Landau tube is squeezed before definitely leaving the Fermi surface, the
Nernst response sharply peaks. In bismuth, additional Nernst peaks, unexpected
in the non-interacting picture, are resolved beyond the quantum limit. The
amplitude of these unexpected Nernst peaks is larger in the samples with the
longest electron mean-free-path.
