‘Magnetricity’ observed and measured for the first time
A magnetic charge can behave and interact just like an electric charge in some materials, according to new research led by the London Centre for Nanotechnology
Story courtesy of London Centre for Nanotechnology (LCN)
The research findings prove the existence of atom-sized magnetic charges called ‘magnetic monopoles’ that behave and interact just like more familiar electric charges. It also demonstrates a perfect symmetry between electricity and magnetism – a phenomenon dubbed ‘magnetricity' by the authors from the LCN and the Science and Technology Facilities Council’s (STFC’s) ISIS Neutron and Muon Source.
In order to prove experimentally the existence of magnetic current for the first time, the team mapped Onsager's 1934 theory of the movement of ions in water onto magnetic currents in a material called spin ice. They then tested the theory by applying a magnetic field to a spin ice sample at a very low temperature and observing the process using muon relaxation at ISIS, a technique which acts as a super microscope allowing researchers to understand the world around us at the atomic level.
The experiment allowed the team to detect magnetic charges in the spin ice (Dy2Ti2O7), to measure their currents, and to determine the elementary unit of the magnetic charge in the material. The monopoles they observed arise as disturbances of the magnetic state of the spin ice, and can exist only inside the material.