Topotactical Hydrogen Induced Single-Band d-Wave Superconductivity in La_{2}NiO_{4}

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• La_{2}NiO_{4} is an antiferromagnetic insulator structurally similar to La_{2}CuO_{4}.
• Unlike cuprates, nickelates have a 3d$^{8}$ electronic configuration, making conventional doping for superconductivity challenging.

Purpose of the Study:

• To explore an alternative route to achieve superconductivity in nickelates.
• To investigate the potential of hydrogen intercalation in tuning the electronic properties of La_{2}NiO_{4}.

Main Methods:

• Density-functional theory (DFT) calculations.
• Dynamical mean-field theory (DMFT) and dynamical vertex approximation (DVA).
• Electric-field-controlled protonation for hydrogen intercalation.

Main Results:

• Hydrogen intercalation transforms La_{2}NiO_{4} into a 3d$_{x^{2}-y^{2}}$ single-band two-dimensional antiferromagnetic Mott insulator.
• Theoretical predictions indicate that H-La_{2}NiO_{4} can exhibit d-wave superconductivity with a critical temperature over 20 K upon 15% hole doping.

Conclusions:

• Hydrogen intercalation offers a novel strategy for tuning the electronic structure of layered nickelates.
• This study provides theoretical evidence for a new class of nickelate superconductors, warranting experimental validation.