GIQS

Graphene impedance quantum standard

EMPIR project 18SIB07

The marketability of electronic products relies on quantifications of voltage, resistance, and impedance. While the major metrology institutes offer ‘gold standard’ traceability for voltage and resistance, by applying Josephson (JE) and quantum Hall effects (QHE), calibrating impedance traceable to the QHE is costly. Cheaper routes to traceability for impedance quantities (ohm, farad, and henry), linked to the defining constants of the revised SI units, would boost supply chains by enabling affordable, traceable measurement services, by a broader range of providers.

 

The project will establish a new primary standard for impedance, linked to the revised SI Units, by exploiting quantum effects of graphene. Novel digital impedance measurement bridges combined with a simpler cooling method will result in a graphene-based quantum Hall resistance device. This will enable a cheaper and easier-to-operate primary standard, and more affordable measurement services. The project will also help link other electrical units to the revised SI units, while new devices will become possible in the technology sector, for faster, more sensitive measurement methods.

OBJECTIVES
  • To optimise and to tailor graphene material and graphene devices in order to improve the understanding of the graphene AC quantised Hall effect (AC-QHE);
  • To advance digital bridges for the capacitance range from 10 pF to 10 nF at frequencies up to 100 kHz, and to develop an impedance bridge working with spectrally pure Josephson voltages up to 50 kHz in the entire complex plane.
  • To combine graphene devices with a Josephson impedance bridge (with a target uncertainty below 0.01 μΩ/Ω), and with a full digital bridge for simplified operation, in order to provide traceability for capacitance to the QHE.
  • To develop and investigate a cryo-cooler system hosting the superconducting Josephson device and the graphene device;
  • To facilitate the take up of the technology and measurement infrastructure developed in the project by graphene manufacturers, NMIs and calibration centres as well as the European Commission’s Graphene Flagship.
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Last modified: 11/02/2021 - 09:27