Phys.org reports Metallic hydrogen, once theory, becomes reality. "The material - atomic metallic hydrogen - was created by Thomas D. Cabot Professor of the Natural Sciences Isaac Silvera and post-doctoral fellow Ranga Dias. In addition to helping scientists answer fundamental questions about the nature of matter, the material is theorized to have a wide range of applications, including as a room-temperature superconductor. The creation of the rare material is described in a January 26 paper published in Science."
It goes on to describe it's possible uses. The NY Times reports that there's some skepticism, Hydrogen Squeezed Into a Metal, Possibly Solid, Harvard Physicists Say. "But in the small but contentious field of high-pressure physics, some scientists who perform similar experiments were harshly skeptical and wondered how the research passed peer review at a top journal like Science."
There's been other reports of its creation but without looking into it much it's not clear to me if those were all debunked.