Magnetic phases and electron-phonon coupling in La${}_3$Ni${}_2$O${}_7$ under pressure

Abstract

Motivated by recent reports of pressure-induced superconductivity in bilayer nickelate La${}_3$Ni${}_2$O${}_7$, we present a comprehensive investigation into the structural, electronic, magnetic, and phonon properties of this compound across a pressure range of 0 to 29.5 GPa. DFT+U calculations reveal that the A-type antiferromagnetic ground state of La${}_3$Ni${}_2$O${}_7$ persists throughout the studied pressure range. Electronic structure analysis shows that the Ni-$d_{xy}$ and Ni-$d_{z^2}$ orbitals dominate near the Fermi level in both the $Fmmm$ and $Amam$ phases of La${}_3$Ni${}_2$O${}_7$. Phonon dispersion calculations for the $Fmmm$ phase reveal no imaginary modes from 12 to 29.5 GPa, confirming its dynamical stability in this pressure range. The vibrational frequencies of O atoms are substantially higher than those of Ni and La atoms, primarily due to the lower mass of oxygen. At 29.5 GPa, the electron-phonon coupling constant $\lambda$ for the $Fmmm$ phase is calculated to be 0.13. This small value suggests that conventional electron-phonon coupling is insufficient to explain the reported superconductivity in La${}_3$Ni${}_2$O${}_7$, indicating a potentially unconventional mechanism. The study offers nuanced, actionable insights that can strategically inform and direct subsequent experimental investigations into the design and optimization of nickel-based superconducting materials.

References in corpus (16)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Superconductivity near 80 Kelvin in single crystals of La3Ni2O7 under pressure
• A superconducting praseodymium nickelate with infinite layer structure
• Bilayer two-orbital model of La${}_3$Ni${}_2$O${}_7$ under pressure
• Possible $S_{\pm }$-wave superconductivity in La${}_3$Ni${}_2$O${}_7$
• The s${}^{\pm }$-Wave Pairing and the Destructive Role of Apical-Oxygen Deficiencies in La${}_3$Ni${}_2$O${}_7$ Under Pressure
• Interlayer Coupling Driven High-Temperature Superconductivity in La${}_3$Ni${}_2$O${}_7$ Under Pressure
• Orbital-Dependent Electron Correlation in Double-Layer Nickelate La3Ni2O7
• Evidence for charge and spin order in single crystals of La${}_3$Ni${}_2$O${}_7$ and La${}_3$Ni${}_2$O${}_6$
• Nickelate superconductors $--$ Multiorbital nature and spin freezing
• High-$T_c$ superconductivity by mobilizing local spin singlets and possible route to higher $T_c$ in pressurized La${}_3$Ni${}_2$O${}_7$
• Electron correlations and superconductivity in La${}_3$Ni${}_2$O${}_7$ under pressure tuning
• Pressure Driven Fractionalization of Ionic Spins Results in Cupratelike High-$T_c$ Superconductivity in La${}_3$Ni${}_2$O${}_7$
• Long-Range Structural Order in a Hidden Phase of Ruddlesden-Popper Bilayer Nickelate La${}_3$Ni${}_2$O${}_7$
• Pair correlations in the two-orbital Hubbard ladder: Implications on superconductivity in the bilayer nickelate La${}_3$Ni${}_2$O${}_7$
• DFT+U+J with linear response parameters predicts non-magnetic oxide band gaps with hybrid-functional accuracy

Cited by in corpus (2)

• Strain-Engineered Electronic Structure and Superconductivity in La${}_3$Ni${}_2$O${}_7$ Thin Films
• Multiorbital character of the density wave in trilayer nickelate superconductors