A diamagnetic substance is slightly repelled by magnetic fields. With a strong enough magnet, the diamagnetic force can override gravity, and the substance will float in the air. Graphite, the main component of pencil lead, is considered one of the best substances for such real-world levitation, and its potential application in sensing weak external perturbations is drawing growing interest.

Until recently, graphite’s electrical conductivity posed an obstacle because electric currents suppress this levitation. Previous research found that a glass coating efficiently blocks the current but also causes the particles to point in all directions, weakening the lifting force.

A team of researchers at Kyoto University happened to be developing a possible solution: making single-crystal equivalents of various substances from fine powders by aligning microcrystals in a uniform direction. Though the scientists specialize in nuclear magnetic resonance spectroscopy, once they came across the graphite levitation issue, they realized they could make a substantial contribution to solving this conundrum.