Single shot spin readout using a cryogenic high-electron-mobility transistor amplifier at sub-Kelvin temperatures

• Published in: Applied physics letters 2016-02, Vol.108 (6)
• Main Authors: Tracy, L. A., Luhman, D. R., Carr, S. M., Bishop, N. C., Ten Eyck, G. A., Pluym, T., Wendt, J. R., Lilly, M. P., Carroll, M. S.
• Format: Article
• Language: English
• Subjects: Amplification; Applied physics; Circuits; Dilution; Electron spin; Electrons; Signal to noise ratio; Single-electron transistors; Transistor amplifiers; Transistor circuits; Transistors; Visibility
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4941421

We use a cryogenic high-electron-mobility transistor circuit to amplify the current from a single electron transistor, allowing for demonstration of single shot readout of an electron spin on a single P donor in Si with 100 kHz bandwidth and a signal to noise ratio of ∼9. In order to reduce the impact of cable capacitance, the amplifier is located adjacent to the Si sample, at the mixing chamber stage of a dilution refrigerator. For a current gain of ∼ 2.7 × 10 3 , the power dissipation of the amplifier is 13 μW, the bandwidth is ∼ 1.3  MHz, and for frequencies above 300 kHz the current noise referred to input is ≤ 70  fA/ Hz . With this amplification scheme, we are able to observe coherent oscillations of a P donor electron spin in isotopically enriched 28Si with 96% visibility.