Field-independent low-temperature thermometry.
Description:
Several methods of low-temperature thermometry are routinely applied, e.g.thick-film resistors based on RuO2. RuO2-based resistors have a good response in the temperature range 0.05 < T(K) < 1. The disadvantage: the respective output is influenced by an applied magnetic field.
At the HLD, two methods of low-temperature thermometry insensitive to the effects of magnetic fields are available. Coulomb Blockade Thermometry operates in the so-called weak Coulomb blockade regime and exploits single-electron tunneling effects. Field independence between 0.2 and 14 Tesla has been shown. As a primary thermometer, it can be used for calibration purposes.
In comparison, capacitance thermometry using sandwiched Ag- and Kapton foils on an Ag rod is less complex and yields robust, secondary thermometers. They can cover a wide temperature range, being insensitive to fields up to 45 T.
| FEATURES | DRESDEN | DRESDEN |
|---|---|---|
| Method | Coulomb Blockade Thermometry | Capacitance Thermometry |
| Temperature range | 50 < T (mK) < 300 | 20 < T (mK) < 2000 |
| Sensitivity | 5% | |
| Probe |  |
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| Quality of the signal |  |
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| Typical experiment | Primary thermometer, calibration | Secondary thermometer |
| Further information | Capacitance thermometer for use at low temperatures and high magnetic fields, T. P. Murphy, E. C. Palm, L. Peabody, and S. W. Tozer, Rev. Sci. Instrum. 72, 3462 (2001) |