Classical Nernst engine.
We introduce a simple model for an engine based on the Nernst effect. In the presence of a magnetic field, a vertical heat current can drive a horizontal particle current against a chemical potential. For a microscopic model invoking classical particle trajectories subject to the Lorentz force, we prove a universal bound 3-2√2≃0.172 for the ratio between the maximum efficiency and the Carnot efficiency. This bound, as the slightly lower one 1/6 for efficiency at maximum power, can indeed be saturated for a large magnetic field and small fugacity.
II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany.
Julian
J
Stark
II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany.
Kay
K
Brandner
Department of Physics, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
Keiji
K
Saito
II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany.
Udo
U
Seifert