At the moment, they have no clue about the disappearance of what was the only metallic hydrogen sample ever known.
Last month, researchers at Harvard revealed they managed to create the very first sample of metallic hydrogen.
As per Tech Times report, "Silvera and Dias are confident about their work and even urged other teams to try to reproduce the experiment as they have already shown how they achieved the high pressures and material in the lab". It was enclosed in a diamond vice under nearly absolute zero conditions, but it has disappeared.
Last month physicists from Harvard University in the USA had claimed to have successfully turned hydrogen into a metal - something researchers had been struggling to achieve for more than 80 years.
"One prediction that's very important is metallic hydrogen is predicted to be meta-stable", Silvera said. 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. It is considered to be the holy grail of physics.
The sample was stored in the lab at a temperature of nearly absolute zero in a diamond vice.
The research team at the Harvard University lead by Dias and Silvera explained that a DAC (diamond anvil cell) was used for this objective that is capable of withstanding pressures as high as 495 GigaPascals.
Superconductors are now used in a variety of applications, for example, in magnetic resonance imaging machines and need to be cooled with liquid helium to keep them at extremely low temperatures.
However, this unique piece seems to be missing. Scientists don't know it if was misplaced - which means it could be somewhere else inside of the lab at room temperature- or if it just degraded back to its natural gas state. "The name 'Metallic Hydrogen" came in highlight when Eugene Wigner and Hillard Bell Huntington (Physicists) in the year 1935 claimed that Hydrogen can exist in Metallic form also under high pressure.
After more than four decades of work on metallic hydrogen, and almost a century after it was first theorized, seeing the material for the first time, Silvera said, was thrilling.
When the pair used a low-pressured laser to measure the pressure of the system earlier this month though, the energy from the layer appears to have destroyed the diamond vice. "Ranga was running the experiment, and we thought we might get there, but when he called me and said, 'The sample is shining, ' I went running down there, and it was metallic hydrogen". Physicist Eugene Gregoryanz, from the University of Edinburgh, said that part of the problem is that the researchers took only one detailed measurement of their sample at the highest pressure, which makes it hard to know how pressure shifted during the experiment.
If scientists can reproduce the conditions of the experiment hereafter, they'd be changing science. According to Silvera, the metallic hydrogen could be useful in everything from our electrical grid to hospital MRI machines.