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arXiv · 0705.2964

Crossover from time-correlated single-electron tunneling to that of Cooper pairs

J. Bylander·T. Duty·G. Johansson·P. Delsing
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Abstract

We have studied charge transport in a one-dimensional chain of small Josephson junctions using a single-electron transistor. We observe a crossover from time-correlated tunneling of single electrons to that of Cooper pairs as a function of both magnetic field and current. At relatively high magnetic field, single-electron transport dominates and the tunneling frequency is given by f=I/e, where I is the current through the chain and e is the electron's charge. As the magnetic field is lowered, the frequency gradually shifts to f=I/2e for I>200 fA, indicating Cooper-pair transport. For the parameters of the measured sample, we expect the Cooper-pair transport to be incoherent.

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J. Bylander, T. Duty, G. Johansson, P. Delsing. 2007-11-07. Crossover from time-correlated single-electron tunneling to that of Cooper pairs. https://doi.org/10.1103/physrevb.76.020506

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