Hidden k-space magnetoelectric multipoles in nonmagnetic ferroelectrics

DOI: 10.1103/PhysRevLett.128.116402

Authors: Sayantika Bhowal (ETH Zurich) , Stephen P. Collins (Diamond Light Source) , Nicola A. Spaldin (ETH Zurich)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review Letters , VOL 128

State: Published (Approved)
Published: March 2022

Abstract: In condensed matter systems, the electronic degrees of freedom are often entangled to form complex composites, known as hidden orders, which give rise to unusual properties, while escaping detection in conventional experiments. Here we demonstrate the existence of hidden k -space magnetoelectric multipoles in nonmagnetic systems with broken space-inversion symmetry. These k -space magnetoelectric multipoles are reciprocal to the real-space charge dipoles associated with the broken inversion symmetry. Using the prototypical ferroelectric PbTiO 3 as an example, we show that their origin is a spin asymmetry in momentum space resulting from the broken space inversion symmetry associated with the ferroelectric polarization. In PbTiO 3 , the k -space spin asymmetry corresponds to a pure k -space magnetoelectric toroidal moment, which can be detected using magnetic Compton scattering, an established tool for probing magnetism in ferromagnets or ferrimagnets with a net spin polarization, which has not been exploited to date for nonmagnetic systems. In particular, the k -space magnetoelectric toroidal moment combined with the spin-orbit interaction manifest in an antisymmetric magnetic Compton profile that can be reversed using an electric field. Our work suggests an experimental route to directly measuring and tuning hidden k -space magnetoelectric multipoles via specially designed magnetic Compton scattering measurements.

Journal Keywords: Ferroelectrics; Compton scattering; Density functional theory

Diamond Keywords: Ferroelectricity

Subject Areas: Materials, Physics


Technical Areas:

Added On: 04/04/2022 11:23

Documents:
PhysRevLett.128.116402.pdf

Discipline Tags:

Quantum Materials Physics Hard condensed matter - structures Magnetism Materials Science

Technical Tags: