Selected Publications

Environment-Assisted Tunneling as an Origin of the Dynes Density of States

J.P. Pekola, V.F. Maisi, S. Kafanov, N. Chekurov, A. Kemppinen, Yu.A. Pashkin, O.-P. Saira, M. Möttönen, J.S. Tsai

We show that the effect of a high-temperature environment in current transport through a normal metal–insulator–superconductor tunnel junction can be described by an effective density of states in the superconductor. In the limit of a resistive low-Ohmic environment, this density of states reduces into the well-known Dynes form. Our theoretical result is supported by experiments in engineered environments. We apply our findings to improve the performance of a single-electron turnstile, a potential candidate for a metrological current source.

Phys. Rev. Lett. 105, 026803 (2010)

doi: 10.1103/PhysRevLett.105.026803