title: Prediction of a Mobile Solid State in Dense Hydrogen under High Pressures.
abstract: Solid rigidity and liquid-scale mobility are thought to be incompatible in elemental substances. One cannot have an elemental solid that is long-range positionally ordered wherein the atoms flow like in a liquid simultaneously. The only exception might be the hypothetical supersolid state of4He. In this work, we demonstrate that such exotic state could exist even in the classical regime. Using ab initio molecular dynamics (AIMD) and ab initio path integral molecular dynamics (AI-PIMD), a novel state of dense hydrogen that simultaneously has both long-range spatial ordering and liquid-scale atomic mobility is discovered at 1 to 1.5 TPa (1 TPa ≈ 10 000 000 atmospheric pressures). The features distinct from a normal solid and liquid are carefully characterized, and the stability and melting behavior are investigated. Extensive AI-PIMD simulations further revealed that this state might be (meta-)stable even at ultralow temperatures, suggesting an emerging candidate for an alternative type of supersolid state in dense metallic hydrogen.
authors.affiliation: National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP ; P.O. Box 919-102 Mianyang, Sichuan P. R. China , 621900.
authors.forename: Hua Y
authors.identifier: http://orcid.org/0000-0001-5757-3027
authors.initials: HY
authors.lastname: Geng
authors.affiliation: National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP ; P.O. Box 919-102 Mianyang, Sichuan P. R. China , 621900.
authors.forename: Q
authors.initials: Q
authors.lastname: Wu
authors.affiliation: National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, CAEP ; P.O. Box 919-102 Mianyang, Sichuan P. R. China , 621900.
authors.forename: Y
authors.initials: Y
authors.lastname: Sun