THERMO-COULOMB EFFECTS IN MESOSCOPIC TUNNEL-JUNCTIONS

We present a study of the thermoelectric effects in tunnel junctions. In particular we calculate the thermopower coefficient S and the Peltier coefficient-PI. For macroscopic junctions we demonstrate the sensitivity of S and PI to the structure of the density of states. For mesoscopic junctions we show that Coulomb effects modify the ordinary Onsager picture and the relation PI = TS. The coefficients S and PI are found to be very sensitive to the coupling of the junctions to the external world. We analyze measurements of the thermopower in granular films in terms of the thermo-Coulomb effects. We comment on the relevance of these effects to scanning tunneling microscope measurements.