At present, metal hydrides are considered highly promising materials for phonon-mediated superconductors that exhibit high values of the critical temperature. In the present study, the superconducting properties of the compressed selenium hydride in its simplest form (HSe) are analyzed, toward quantitative characterization of this phase. By using the state-of-art Migdal-Eliashberg formalism, it is shown that the critical temperature in this material is relatively high ([Formula: see text][Formula: see text]K) and surpasses the level of magnesium diboride superconductor, assuming that the Coulomb pseudopotential takes value of [Formula: see text]. Moreover, the employed theoretical model allows us to characterize other pivotal thermodynamic properties such as the superconducting band gap, the free energy, the specific heat, and the critical magnetic field. In what follows, it is shown that the characteristic thermodynamic ratios for the aforementioned parameters differ from the predictions of the Bardeen-Cooper-Schrieffer theory. As a result, we argue that strong-coupling and retardation effects play important role in the discussed superconducting state, which cannot be described within the weak-coupling regime.

中文翻译：

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压缩氢化硒中超导相的强耦合特性

目前，金属氢化物被认为是具有高临界温度的声子介导超导体的非常有前景的材料。在本研究中，分析了最简单形式的压缩氢化硒 (HSe) 的超导特性，以对该相进行定量表征。通过使用最先进的 Migdal-Eliashberg 形式，表明该材料的临界温度较高（[公式：见正文][公式：见正文]K）并超过二硼化镁超导体的水平，假设库仑赝势取值为 [公式：见正文]。此外，所采用的理论模型使我们能够表征其他关键的热力学性质，例如超导带隙、自由能、比热、和临界磁场。在下文中，表明上述参数的特征热力学比与 Bardeen-Cooper-Schrieffer 理论的预测不同。因此，我们认为强耦合和延迟效应在所讨论的超导状态中起着重要作用，这在弱耦合状态下是无法描述的。