A SQUID-Based Picovoltmeter for Quantum Resistors
A SQUID-Based Picovoltmeter for Quantum Resistors
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DOI：
10.1007/s10909-020-02388-4
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发表时间：
2020-02
影响因子：
2
通讯作者：
V. Shingla;E. Kleinbaum;G. Csáthy
中科院分区：
文献类型：
--
作者：
V. Shingla;E. Kleinbaum;G. Csáthy
我们提出了一种灵敏的电压放大器，适用于测量稀释冰箱温度下的k范围内的源阻抗。该电路是基于一个商业直流SQUID，一个阻抗匹配Transformer，它的工作原理是负反馈。在10 mK时，放大器对噪声的贡献仅为17，这与3.25 k金属源电阻器的热电压波动相比可以忽略不计。讨论了放大器的各种电路参数。
We present a sensitive voltage amplifier suited for measurements of source impedances in the krange at dilution refrigerator temperatures. The circuit is based on a commercial dc SQUID, an impedance matching transformer, and it works on the principle of negative feedback. At 10 mK, the amplifier contribution to the noise is only 17, which is negligible in comparison with the fluctuations of the thermal voltage of a 3.25 kmetallic source resistor. Various circuit parameters of the amplifier are discussed.