98 / 2023-04-13 17:37:10

Stress-induced high-Tc superconductivity in solid molecular hydrogen

high pressure,metallic hydrogen,anisotropic stresses,superconductivity,first-principles calculations

高压物理与材料科学 > 氢与高能量密度材料-海报

Metallic hydrogen has long been considered the Holy Grail of high-pressure physics that holds the intriguing possibility of realizing room-temperature superconductivity [1,2]. However, the ultrahigh pressures required for hydrogen metallization impose severe experimental challenges and constraints on synthesis and characterization, leaving large ambiguities and controversies in the interpretation of reported results [3-5]. Meanwhile, little is known about the influence of nonhydrostatic conditions on its electronic properties at extreme pressures where anisotropic stresses are inevitably present and may also be intentionally introduced [6]. Here we show by first-principles calculations that solid molecular hydrogen compressed to multimegabar pressures can sustain large anisotropic compressive or shear stresses that, in turn, cause major crystal symmetry reduction and charge redistribution that accelerate bandgap closure and promote superconductivity relative to pure hydrostatic compression. Our findings highlight a hitherto largely unexplored mechanism for creating superconducting dense hydrogen, with implications for exploring similar phenomena in hydrogen-rich compounds and other molecular crystals.