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arXiv · 1005.3180

Charge noise at Cooper-pair resonances

P. G. Kirton·M. Houzet·F. Pistolesi·A. D. Armour
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Abstract

We analyze the charge dynamics of a superconducting single-electron transistor (SSET) in the regime where charge transport occurs via Cooper-pair resonances. Using an approximate description of the system Hamiltonian, in terms of a series of resonant doublets, we derive a Born-Markov master equation describing the dynamics of the SSET. The average current displays sharp peaks at the Cooper-pair resonances and we find that the charge noise spectrum has a characteristic structure which consists of a series of asymmetric triplets of peaks. The strongest feature in the charge noise spectrum is the triplet of peaks centered at zero frequency which has a peak spacing equal to the level separation within the doublets and is similar to the triplet in the spectrum of a driven, damped, two-level system. We also explore the back-action that the SSET charge noise would have on an oscillator coupled to the island charge, measurement of which provides a way of probing the charge noise spectrum.

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P. G. Kirton, M. Houzet, F. Pistolesi, A. D. Armour. 2010-08-25. Charge noise at Cooper-pair resonances. https://doi.org/10.1103/physrevb.82.064519

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