Editor's Summary
15 October 2009
'Magnetricity' demonstrated in spin ice
Electric charges and currents are ubiquitous, but their magnetic counterparts are elusive. With the recent prediction, then demonstration, of the existence of magnetic 'monopoles' — particles with a net magnetic charge resembling a magnet with only one pole — in magnetically frustrated materials called 'spin ice', a system in which 'magnetricity' might be found has become available. Using the spin ice dysprosium titanate pyrochlore (Dy2Ti2O7), Bramwell et al. show that magnetic charges and their dynamics can be understood in terms of a magnetic analogue of the theory of electrolytes (substances that become ions in solution and are capable of conducting electricity). They observe real magnetic currents and determine the elementary unit of magnetic charge. The findings establish an instance of a perfect symmetry between electricity and magnetism.
Authors: Making the paper: Steven Bramwell & Sean Giblin
'Magnetricity' sees monopoles flowing in a magnetic field.
doi:10.1038/7266846a
News and Views: Condensed-matter physics: Wien route to monopoles
Determining the magnetic charge of monopoles in a crystalline host seemed a mountain too high for physicists to climb. An experiment based on Wien's theory of electrolytes has now measured its value.
Shivaji Sondhi
doi:10.1038/461888a
Letter: Measurement of the charge and current of magnetic monopoles in spin ice
S. T. Bramwell, S. R. Giblin, S. Calder, R. Aldus, D. Prabhakaran & T. Fennell
doi:10.1038/nature08500
