Unconventional superconductivity without doping in infinite-layer nickelates under pressure.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Materials

Background:

• High-temperature unconventional superconductivity often arises from doped, strongly correlated antiferromagnetic insulators.
• Dynamical vertex approximation (DVA) is a cutting-edge method that accurately predicted nickelate superconducting properties.

Purpose of the Study:

• To investigate the impact of pressure on superconductivity in infinite-layer nickelates (Sr_xPr_1-xNiO₂).
• To explore the potential for enhanced critical temperatures (T_c) in nickelate superconductors under elevated pressures.

Main Methods:

• Application of the dynamical vertex approximation (DVA) to model Sr_xPr_1-xNiO₂ under pressure.
• Theoretical calculation of superconducting critical temperature (T_c) as a function of applied pressure.

Main Results:

• The study successfully reproduces the experimentally observed increase in T_c with pressure up to 12 GPa.
• Theoretical predictions indicate that T_c can be further enhanced at higher pressures.
• Even the undoped parent compound, PrNiO₂, is predicted to become a high-temperature superconductor due to pressure-induced self-doping.

Conclusions:

• Pressure is a crucial tuning parameter for enhancing superconductivity in nickelates.
• Nickelate superconductors, under optimal pressure conditions, can achieve critical temperatures comparable to the best cuprate superconductors, reaching up to 100 K at approximately 100 GPa.