Single Electron Effects in Small Tunnel Junctions

Abstract

With modern lithographic techniques tunnel junctions with areas smaller than 10-2 μm2 can be fabricated in a controlled fashion corresponding to capacitances as small as C ≈ 10-16 F (see Geerligs and Mooij, this volume). Charging effects in these systems strongly influence the transport properties at low temperatures. The basic theoretical description of these effects is by now well established. A comprehensive summary of this description is presented in section 2. In section 3 we discuss some selected extensions of the basic theory, still using a perturbative approach. In many experiments the influence of the external circuit on the charging effects is not negligible, and recent developments of the theory concentrated on these effects. Frequently it requires a non-perturbative approach. We, therefore, summarize in section 4 the formulation of the macroscopic quantum dynamics with arbitrary dissipation and apply it to several selected problems in section 5. For more extensive reviews of the field we refer to two recent articles [1, 2].