Solitonic lattice and Yukawa forces in the rare earth orthoferrite TbFeO3

TL;DR

This paper reports the discovery of a novel magnetic state in TbFeO3 characterized by a long incommensurate period and Yukawa-like interactions between domain walls, revealing complex multiferroic domain dynamics.

Contribution

It introduces a new magnetic state in TbFeO3 with a Yukawa-like force between domain walls, linking magnetic interactions to particle physics concepts.

Findings

Long incommensurate magnetic period varies with temperature.

Presence of higher-order harmonics indicating sharp domain walls.

Yukawa-like force mediates interactions between domain walls.

Abstract

The control of domains in ferroic devices lies at the heart of their potential for technological applications. Multiferroic materials offer another level of complexity as domains can be either or both of a ferroelectric and magnetic nature. Here we report the discovery of a novel magnetic state in the orthoferrite TbFeO3 using neutron diffraction under an applied magnetic field. This state has a very long incommensurate period ranging from 340 Angstrom at 3K to 2700 Angstrom at the lowest temperatures and exhibits an anomalously large number of higher-order harmonics, allowing us to identify it with the periodic array of sharp domain walls of Tb spins separated by many lattice constants. The Tb domain walls interact by exchanging spin waves propagating through the Fe magnetic sublattice. The resulting Yukawa-like force, familiar from particle physics, has a finite range that determines the period of the incommensurate state.