2008/05/07 by W. W. Xue, Xue, W. W., Z. Ji +7
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Superconductivity (cond-mat.supr-con) #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.0805.1037
5 pages, 4 figures
arxiv created 2008/05/07 · arxiv updated 2009/12/01
We have directly measured the quantum noise of a superconducting single-electron transistor (S-SET) embedded in a microwave resonator consisting of a superconducting LC tank circuit. Using an effective bath description, we find that the S-SET provides damping of the resonator modes proportional to its differential conductance and has an effective temperature that depends strongly on the S-SET bias conditions. In the vicinity of a double Cooper pair resonance, when both resonances are red detuned the S-SET effective temperature can be well below both the ambient temperature and the energy scale of the bias voltage. When blue detuned, the S-SET shows negative differential conductivity,