Thermoelectric effects in superconductors

Thermoelectric effects in superconductors began to be studied about 50 years ago, but until recently the opinion was widespread that they completely vanish in the superconducting state. Yet as far back as 1944 attention was called to the fact that distinctive thermoelectric effects should arise within the framework of the two-fluid concept (allowing for the possible existence in a superconductor of a normal current as well as a superconducting current). Concretely, in an isotropic but inhomogeneous superconductor, or else in a homogeneous but anisotropic one, a thermocurrent and a magnetic field associated with it should arise in the presence of a temperature gradient. Generally these effects are small, yet in recent years they have become accessible to measurement, and a number of pertinent experimental studies have appeared. On the other hand, progress has also been made in the field of theory, in particular, in understanding the nature and various features of thermoelectric phenomena in superconductors. This article is devoted to a general physical and more detailed theoretical analysis of the problem of thermoelectric effects in superconductors. The content of the article in greater detail is evident from the table of contents.