IN THE 1980s, “high-temperature superconductors” promised everything from
magnetically levitating trains to resistance-free power lines and cheap MRI
scanners. They have failed to deliver largely because they could not carry
enough current. Now a new material will not only do the key trick of conducting
with zero resistance but has overtaken its rivals on the amount of current it
can carry.
The abilities of the new material, magnesium diboride (MgB2),
sparked a huge research effort across the world after it was shown to
superconduct earlier this year. The “off-the-shelf” chemical loses all
electrical resistance when cooled to 39 kelvin.…
