High-temperature superconductivity in hydrides: experimental evidence and details

Abstract

Since the discovery of superconductivity at 200 K in H3S [1] similar or higher transition temperatures, Tcs, have been reported for various hydrogen-rich compounds under ultra-high pressures [2]. Superconductivity was experimentally proved by different methods, including electrical resistance, magnetic susceptibility, optical infrared, and nuclear resonant scattering measurements. The crystal structures of superconducting phases were determined by X-ray diffraction. Numerous electrical transport measurements demonstrate the typical behaviour of a conventional phonon-mediated superconductor: zero resistance below Tc, the shift of Tc to lower temperatures under external magnetic fields, and pronounced isotope effect. Remarkably, the results are in good agreement with the theoretical predictions, which describe superconductivity in hydrides within the framework of the conventional BCS theory. However, despite this acknowledgment, experimental evidence for the superconducting state in these compounds has recently been treated with criticism [3, 4], which apparently stems from misunderstanding and misinterpretation of complicated experiments performed under very high pressures. Here, we describe in greater detail the experiments revealing high-temperature superconductivity in hydrides under high pressures. We show that the arguments against superconductivity [3, 4] can be either refuted or explained. The experiments on the high-temperature superconductivity in hydrides clearly contradict the theory of hole superconductivity [4] and eliminate it [3].

References in corpus (9)

• Exploration of new superconductors and functional materials and fabrication of superconducting tapes and wires of iron pnictides
• Superconducting Phase-Diagram of H3S under High Magnetic Fields
• Nonstandard superconductivity or no superconductivity in hydrides under high pressure
• Superconductivity up to 243 K in yttrium hydrides under high pressure
• Conventional superconductivity at 190 K at high pressures
• Anomalous behavior in high-pressure carbonaceous sulfur hydride
• Hole superconductivity in $H_{2}S$ and other sulfides under high pressure
• Unexpected stable stoichiometries of sodium chlorides
• Intrinsic hysteresis in the presumed superconducting transition of hydrides under high pressure

Cited by in corpus (2)

• Hydride superconductivity: here to stay
• High-pressure magnetic transition in iron observed via diamond quantum sensing