Finite-Temperature Current-Voltage Characteristics of Ultrasmall Tunnel Junctions

G.-L. Ingold and H. Grabert

Europhys. Lett. 14, 371–376 (1991) DOI: 10.1209/0295-5075/14/4/015

The current-voltage characteristics of tunnel junctions are studied in a region where charging effects are important. The influence of the electromagnetic environment on the Coulomb blockade is described in terms of the probability P(E) that a tunneling electron looses the energy E to the environment. This quantity depends only on the external impedance shunting the junction. Given P(E), the tunneling current for normal as well as superconducting tunnel junctions can be calculated for finite temperatures and any impedance. It is shown that the density of environmental modes becomes primarily observable in differential current-voltage characteristics.