摘要
The behavior of hydrogen under extreme pressure has continued to attract great interest among the physics,chemistry,materials science,and geoscience communities and has become a major driving incentive for cross-disciplinary advances in novel high-pressure technology.This has been particularly noticeable this year,and is one of the main themes of this“Special Issue on High Pressure Science 2021.”Hydrogen exhibits a rich physics of multiple phase transitions,including a predicted novel quantum state combining superconductivity and superfluidity upon metallization,and also provides benchmark values for testing theoretical models of quantum solids at high densities.
