Graphensic, the Linkoping University spin-off and supplier of graphene on silicon carbide (SiC), launched a graphene-based resistance standard called the GRS, aimed at utilizing the ability to observe the quantum Hall effect at relatively low magnetic fields and high temperatures.
The GRS offers a solution to perform precise and relatively simple calibrations of the electrical resistance in terms of the quantum Hall effect. It is equipped with a superconducting magnet and comes with a graphene-based QHE chip. The only complementary equipment needed is a liquid helium storage dewar to provide the needed refrigeration. After the GRS is connected to a measurement system, resistance measurements can start within an hour. Since the GRS is not cumbersome in size, it allows the convenient performance of on-site comparisons of the quantum Hall resistance standard.
The company states that by utilising the characteristics of epitaxial graphene on silicon carbide, the experimental equipment can be significantly improved. With these graphene devices, the quantum Hall effect can be observed at magnetic fields of 5 T and temperatures around 4.2 K. Instead of using a cryostat it is now possible to rely on local liquid helium storage dewars for refrigeration. This significantly eases the procedure of setting up the equipment, as well as the transportation of the system.