IEEE Transactions on Nanotechnology

Near-Quantum-Limited Operation of a Charge-Sensitive Electrical Amplifier

A. J. Rimberg, Wei Wei Xue, Zhongqing Ji, Feng Pan, Joel Stettenheim

Published Jan 1, 2010• 0 citations

Abstract

Here, we report the operation of a superconducting single-electron transistor (S-SET) as a fast and nearly quantum-limited charge-sensitive amplifier. By operating the S-SET such that Cooper pair tunneling is resonant across both of its tunnel junctions, we are able to achieve an excellent charge sensitivity of δq = 1.6 × 10-6e/√(Hz), while also minimizing back action. We find that near its optimal operating point, the S-SET can have both a very low noise temperature Tn≈ 50 mK and a large power gain ASET>;>; 1. These results indicate that our S-SET operates within a factor of 2 of the quantum limit.

DOI: 10.1109/tnano.2010.2064784

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