It is now possible to accurately measure the quantum Hall effect (QHE) in magnetic fields of less than 5 Tesla and at temperatures of just under 4 Kelvin in a cryogen-free tabletop system using devices made from epitaxial graphene on silicon carbide (SiC). The new technique, developed by researchers in the UK and Sweden, is much simpler than traditional methods to measure the QHE that rely on large superconducting magnets and temperatures lower than 1 K. Measuring the QHE is important for determining the SI unit for resistance, the ohm…….
http://nanotechweb.org/cws/article/tech/62387
