‘Antimagnet’ Renders Magnets InvisibleUncategorized Tuesday, March 27th, 2012
(Nature) Physicists have already unveiled invisibility cloaks that can hide objects from light, sound, seismic and even water waves. Now researchers report a cloak that can hide objects from static magnetic fields. This ‘antimagnet’ could have medical applications, but might also subvert airport security.
Writing in Science1, a team of theorists led by Alvaro Sanchez at the Autonomous University of Barcelona in Spain, together with experimentalists at the Slovak Academy of Sciences in Bratislava, describe a magnetic cloak made with inexpensive, readily available materials.
The cloak’s interior is lined with turns of tape made from a high-temperature superconductor. Superconductors repel magnetic fields, so any magnetic field enclosed within a superconductor would be undetectable from outside. But the superconductor itself would still perturb an external magnetic field, so the researchers coated its external side with an ordinary ferromagnet — the material that kitchen fridge magnets are made of. The superconductor tries to repel external field lines, whereas the ferromagnet tries to draw them in — together, the two layers cancel each other out.
Read the full article: