Thermoelectric effect as a test of exotic superconductivity

I show that measurements of thermoelectric effects can provide a simple criterion for distinguishing between ordinary superconductivity and superconductivity characterized by an order parameter with symmetry less than that of the underlying Fermi surface. An externally imposed temperature gradient gives rise generally to circulating currents and magnetic fields which vanish only if the thermoelectric and electromagnetic responses of the superconductor are isotropic. An estimate of the magnitude of this effect suggests that, while in ordinary superconductors these effects are extremely small, a signal in a heavy-fermion superconductor should be detectable.