Hydrogen, the lightest and the most abundant element in the universe becomes a mainstay of contemporary condensed matter physics, which is largely because its metallization is regarded as the holy grail of high-pressure physics and it is also due to r...
Hydrogen, the lightest and the most abundant element in the universe becomes a mainstay of contemporary condensed matter physics, which is largely because its metallization is regarded as the holy grail of high-pressure physics and it is also due to recent observations of high Tc superconductivity in hydrogen-dense compounds at extremely high pressure. Contemporary static high-pressure technique is not enough to realize the metallization of solid hydrogen and hydrogen-dense compounds may significantly reduce the required transition pressure providing an excellent proxy study. In this brief review, I will introduce recent achievements of high-pressure study in solid hydrogen and hydrides.