A New High-Temperature Superconductor Predicted: RbPH₃ Perovskite

Quantum lattice anharmonicity makes it thermodynamically stable at only 25 GPa and metastable down to ambient pressure, where his critical temperature is around 100 kelvin

In a recent publication, our group has predicted a novel perovskite compound, RbPH₃, that exhibits remarkable superconducting properties. What makes this material particularly exciting is its synthesizability at relatively low pressures (25 GPa) and its metastability down to ambient conditions, a rare combination in high-pressure superconducting materials. This opens up promising avenues for experimental realization and potential applications.

The metastability of RbPH₃ is enabled by strong lattice anharmonicity, which stabilizes the structure even after decompression. This behavior is crucial, as it allows the material to retain its superconducting phase outside of extreme environments. Our calculations predict a superconducting critical temperature (Tc) of approximately 100 K, placing RbPH₃ among the few materials that could operate at liquid nitrogen temperatures—a significant milestone in the search for practical superconductors.

This work not only expands the family of perovskite superconductors but also highlights the power of first-principles crystal structure prediction combined with anharmonic phonon calculations. By identifying materials that are both synthesizable and metastable, we move closer to bridging the gap between theoretical predictions and experimental feasibility.