Hydrogen-Based Superconductors: Superconducting Mechanisms under Pressure Tuning and Future Development

Abstract

Hydride superconductors are promising candidates for high-temperature superconductivity across a wide pressure range. This review presents a comprehensive review of their structural, electronic, and superconducting properties, with a focus on how pressure influences phase stability and enhances critical temperature (T_c). We categorize hydrides into three pressure regimes: ambient pressure, low pressure (<100 GPa), and high pressure (>100 GPa). Ambient pressure compounds, such as perovskite-like hydrides and SM₂TMH₆ structures, exhibit moderate T_c values. Low-pressure hydrides benefit from unique strategies like molecular doping and electron precompression to improve their T_c. The high-pressure hydrides exhibit higher T_c values, including room-temperature superconductivity, but require extreme conditions for synthesis and characterization. We also highlight recent theoretical and experimental advances, outlining current challenges and prospects. This review not only highlights the potential of hydride superconductors but also provides a roadmap for future research in this exciting and rapidly developing field.

Keywords

Hydride superconductors / Electron-phonon coupling / Ab initio calculations / Host-guest systems / High-pressure chemistry / Conducting materials

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2025 SIOC, CAS, Shanghai, & WILEY-VCH GmbH