ScienceDaily (Apr. 14, 2010) — Researchers from Imperial College London have created a structure that acts like a single pole of a magnet, a feat that has evaded scientists for decades.
The researchers say their new Nature Physics study takes them a step closer to isolating a 'magnetic monopole.'
Magnets have two magnetic poles, north and south. 'Like' poles, such as north and north, repel one another and 'opposite' poles, such as north and south, attract. Whichever way a magnet is cut, it will always have these two poles.
Scientists have theorised for many years that it must be possible to isolate a 'magnetic monopole', either north or south on its own, but until recently researchers have been unable to show this in experiments.
Researchers at Imperial have now enabled tiny nano-sized magnets to behave like magnetic monopoles, by arranging them in a honeycomb structure.
In late 2009, various teams of scientists reported they had created monopole-like behaviour in a material called 'spin ice'. In these materials, monopoles form only at extremely low temperatures of -270 degrees Celsius.
The Imperial researchers' structure contains magnetic monopoles at room temperature.
- S. Ladak, D. E. Read, G. K. Perkins, L. F. Cohen & W. R. Branford. Direct observation of magnetic monopole defects in an artificial spin-ice system. Nature Physics, 2010; DOI: 10.1038/nphys1628