Magnetic Interactions

Synergy between materials and methods is helping to address open questions in magnetism and superconductivity.

Oxides of non-magnetic cations exhibit elusive signs of weak temperature-independent ferromagnetism. The effect is associated with surface defects, but it defies conventional explanation. Possible hypotheses are a spin-split defect impurity band, or giant orbital paramagnetism related to zero-point vacuum fluctuations.

The chiral magnetic exchange interaction, or Dzyaloshinskii–Moriya interaction, is found to propagate through dozens of atomic layers and also to be present in inhomogeneous amorphous alloys. These discoveries extend the parameter space available for realizing magnetic structures with chiral character.

An antisymmetric and chiral long range interlayer magnetic exchange interaction is measured, with implications for spintronics and chiral magnetic devices.

An interlayer Dzyaloshinskii–Moriya interaction is observed in a synthetic antiferromagnet, with implications for achieving chiral spin textures in multilayered thin films.

A composition gradient is found to provide the necessary structural inversion asymmetry for a bulk Dzyaloshinskii–Moriya interaction to manifest itself.

Extreme electronic anisotropy is revealed in the high-temperature superconductor FeSe through tour de force experiments on detwinned crystals.