US team claims world first with creation of metallic hydrogen

The material could have a range of applications, including as a room-temperature superconductor, and a rocket fuel that could help humans explore the far reaches of space.

Described by lead researcher Prof Isaac Silvera as “the holy grail of high pressure physics”, the breakthrough is detailed in a paper published in the latest issue of Science.

“It’s the first-ever sample of metallic hydrogen on Earth,” said Silvera, “so when you’re looking at it, you’re looking at something that’s never existed before.”

To create the material the team squeezed a tiny hydrogen sample at 495 gigapascal (GPa), which is greater than the pressure at the center of the Earth.

At these 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, which is a metal.

While the work creates an important window into understanding the general properties of hydrogen, it also offers tantalising hints at potentially revolutionary new materials.