Physics

Cuprate

Electron

Square lattice

Inelastic neutron scattering

Resonant inelastic X-ray scattering

Inelastic scattering

Antiferromagnetism

Acoustics

Scattering

Condensed matter physics

Lattice (music)

Spins

Ising model

Superconductivity

Quantum mechanics

Doping

Science

The discovery of superconductivity in infinite-layer nickelates brings us tantalizingly close to a new material class that mirrors the cuprate superconductors. Here, we report on magnetic excitations in these nickelates, measured using resonant inelastic x-ray scattering (RIXS) at the Ni L3-edge, to shed light on the material complexity and microscopic physics. Undoped NdNiO2 possesses a branch of dispersive excitations with a bandwidth of approximately 200 meV, reminiscent of strongly-coupled, antiferromagnetically aligned spins on a square lattice, despite a lack of evidence for long range magnetic order. The significant damping of these modes indicates the importance of coupling to rare-earth itinerant electrons. Upon doping, the spectral weight and energy decrease slightly, while the modes become overdamped. Our results highlight the role of Mottness in infinite-layer nickelates.

Magnetic excitations in infinite-layer nickelates