Topological phonons in an inhomogeneously strained silicon-5: Inhomogeneous magnetoelectronic effect in a conductor

TL;DR

This paper provides experimental evidence of inhomogeneous magnetoelectronic effects in a layered Py/p-Si structure, revealing spatial modulations in spin density, magnetic moments, and associated magnetocaloric effects due to topological phonons and charge doping.

Contribution

It demonstrates the first experimental observation of inhomogeneous magnetoelectronic effects in a conducting multiferroic system, linking topological phonons and charge carrier inhomogeneity.

Findings

Spatial modulations in spin density and magnetic moments observed.

Charge carrier density varies with position and magnetic field direction.

Incommensurate SDW with ~142 um wavelength detected.

Abstract

The spatially inhomogeneity in a magnetic crystal give rise to electric polarization, which is known as inhomogeneous magnetoelectric effect. Similarly, an inhomogeneous magnetoelectronic effect in a conducting multiferroic material give rise to spatially inhomogeneous magnetic moment and spin distribution due to spatially inhomogeneity in the charge carrier concentration. In this study, we present experimental evidence of inhomogeneous magnetoelectronic effect in Py/p-Si layered structure. The Py/p-Si layered structure exhibit electronic multiferroicity due to superposition of flexoelectronic charge carrier doping and topological phonons. It gives rise to spatially modulations in the spin density and magnetic moment, which are discovered using the Hall effect measurement. The charge carrier density as well as type of the charge carrier are found to be a function of spatial coordinate as well as direction of magnetic field. The observed modulations can also be interpreted as incommensurate SDW with wavelength of ~142 um. The inhomogeneous magnetoelectronic effect also give rise to magnetocaloric effect, which is uncovered using thermal hysteresis in the magnetoresistance measurement. This is a first experimental evidence of inhomogeneous magnetoelectronic effect, which is electronic counterpart of the magnetoelectric effect.