Effect of high-frequency electrodynamic environment on the single-electron tunneling in ultrasmall junctions

Abstract

Single-electron tunneling in Al/${\mathrm{AlO}}_{\mathrm{x}}$/Al junctions with areas below 0.01 μ${\mathrm{m}}^2$ was studied at temperatures close to 1 K. The junctions, placed in different high-frequency environments but similar in all other aspects, exhibited different dc I-V curves, in accordance with the theory of correlated single-electron tunneling. Our results imply that a tunneling electron can effectively probe its electrodynamic environment at distances much larger than c${\mathrm{\tau }}_{\mathrm{t}}$, where ${\mathrm{\tau }}_{\mathrm{t}}$ is the ‘‘traversal’’ time of its passage through the energy barrier.