Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 5241-5249 |
| Journal | Journal of Applied Physics |
| Volume | 74 |
| Issue number | 8 |
| Publication status | Published - 1993 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- Josephson junction
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Influence of the Josephson junction on the impedance and noise of a resistive superconductive quantum interference device. / Soulen, Robert; Fogle, William; Colwell, Jack; Cohn, Joshua; Seppä, Heikki.
In: Journal of Applied Physics, Vol. 74, No. 8, 1993, p. 5241-5249.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Influence of the Josephson junction on the impedance and noise of a resistive superconductive quantum interference device
AU - Soulen, Robert
AU - Fogle, William
AU - Colwell, Jack
AU - Cohn, Joshua
AU - Seppä, Heikki
PY - 1993
Y1 - 1993
N2 - The impedance and noise of a resistive superconductive quantum interference device (R‐SQUID) have been measured as a function of the dc and rf currents applied to it. The Josephson junction was adjustable so that data were also taken for several values of the junction critical current. The results were compared with the predictions of a resistively shunted junction (RSJ) model which takes into account the influence of the Josephson junction on the impedance and noise. The agreement was found to be quite good and demonstrates that the noise in the circuit is well understood. Use of the R‐SQUID as a noise thermometer below 1 K is assessed in terms of corrections due to the RSJ model. It is demonstrated how the dc and rf currents may be adjusted so that the total noise of the R‐SQUID is reduced to within 0.1% of the Johnson noise generated by the resistor alone. Under these conditions, the R‐SQUID may be used as a noise thermometer to determine thermodynamic temperature to this inaccuracy from 6 to 700 mK.
AB - The impedance and noise of a resistive superconductive quantum interference device (R‐SQUID) have been measured as a function of the dc and rf currents applied to it. The Josephson junction was adjustable so that data were also taken for several values of the junction critical current. The results were compared with the predictions of a resistively shunted junction (RSJ) model which takes into account the influence of the Josephson junction on the impedance and noise. The agreement was found to be quite good and demonstrates that the noise in the circuit is well understood. Use of the R‐SQUID as a noise thermometer below 1 K is assessed in terms of corrections due to the RSJ model. It is demonstrated how the dc and rf currents may be adjusted so that the total noise of the R‐SQUID is reduced to within 0.1% of the Johnson noise generated by the resistor alone. Under these conditions, the R‐SQUID may be used as a noise thermometer to determine thermodynamic temperature to this inaccuracy from 6 to 700 mK.
KW - Josephson junction
M3 - Article
VL - 74
SP - 5241
EP - 5249
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 8
ER -