Nearly a century after it was theorized, scientists from Harvard University have created the first-ever sample of one of the rarest materials on the planet: metallic hydrogen. The atomic metallic hydrogen has a potentially wide range of applications, including as a room-temperature superconductor.

“This is the Holy Grail of high-pressure physics,” said Isaac Silvera, Thomas D. Cabot Professor of the Natural Sciences. “You’re looking at something that’s never existed before.”

In their experiments, Silvera and postdoctoral fellow Ranga Dias squeezed a tiny hydrogen sample at 495 gigapascal (GPa), or more than 71.7 million pounds per square inch — greater than the pressure at the center of the Earth.

At such extreme pressures, solid molecular hydrogen, which consists of molecules on the lattice sites of the solid, breaks down, and the tightly bound molecules dissociate to transform into atomic hydrogen, a metal.

Some researchers predict that the atomic metallic hydrogen has "meta-stable” characteristics, much like diamonds.

"That means if you take the pressure off, it will stay metallic, similar to the way diamonds form from graphite under intense heat and pressure, but remain diamonds when that pressure and heat are removed,” said Silvera.

A room temperature superconductor, according to Dias, could change the transportation system, enabling magnetic levitation of high-speed trains. The material could also provide major improvements in energy production and storage, allowing more powerful rocket propellants needed for humans to explore space.


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