Pumping characteristics were studied of the hybrid normal-metal/superconductor single-electron transistor embedded in a high-ohmic environment. Two 3 micrometer-long microstrip resistors of CrOx with a sum resistance R=80kOhm were placed adjacent to this hybrid device. Substantial improvement of pumping and reduction of the subgap leakage were observed in the low-MHz range. At higher frequencies 0.1-1GHz, a slowdown of tunneling due to the enhanced damping and electron heating negatively affected the pumping, as compared to the reference bare devices.
@article{arxiv.0905.3402,
title = {Pumping properties of the hybrid single-electron transistor in dissipative environment},
author = {S. V. Lotkhov and A. Kemppinen and S. Kafanov and J. P. Pekola and A. B. Zorin},
journal= {arXiv preprint arXiv:0905.3402},
year = {2010}
}