Quantum resistance standard
Campione quantistico resistenza

The laboratory realises the unit of electric resistance, the ohm (Ω), by means of the quantum Hall effect and of the exact value of the von Klitzing constant. The Hall resistance of semiconductor devices (GaAs) is measured in the dc regime and transferred to standard resistors, with a potentiometer or a cryogenic current comparator (CCC) working in the 1 Ω-1 MΩ range.

The available instrumentation allows the characterisation of materials and electronic devices in a wide range of temperatures (300 mK - 300 K) and magnetic fields (0 - 16 T). Further current comparator bridges allow for the extension of the resistance scale down to 1 μΩ and the calibration of direct-current current transducers (DCCT).