Theory of thermoelectric phenomena in superconductors

The theory of thermoelectric effects in superconductors is discussed in connection to the recent publication by Marinescu and Overhauser [Phys. Rev. B 55, 11 637 (1997)]. We argue that the charge nonconservation arguments by Marinescu and Overhauser do not require any revision of the Boltzmann transport equation in superconductors. We show that the charge current proportional to the gradient of the gap, |Δ|, found by Marinescu and Overhauser, is incompatible with the time-reversal symmetry, and conclude that their ``electron-conserving transport theory'' is invalid. Possible mechanisms responsible for the discrepancy between some experimental data and the theory by Galperin, Gurevich, and Kozub {Pis'ma Zh \'Eksp. Teor. Fiz. 17, 687 (1973) [JETP Lett. 17, 476 (1973)]} are discussed.