Large Magnetic Moment in Flexoelectronic Silicon at Room Temperature

Abstract

Time-dependent rotational electric polarizations have been proposed to generate temporally varying magnetic moments, for example, through a combination of ferroelectric polarization and optical phonons. This phenomenon has been called dynamical multiferroicity, but explicit experimental demonstrations have been elusive to date. Here, we report the detection of a temporal magnetic moment as high as 1.2 mu_B/atom in charge-doped thin film of silicon under flexural strain. We demonstrate that the magnetic moment is generated by a combination of electric polarization arising from a flexoelectronic charge separation along the strain gradient and the deformation potential of phonons. The effect can be controlled by adjusting the external strain gradient, doping concentration and dopant, and can be regarded as a dynamical multiferroic effect involving flexoelectronics polarization instead of ferroelectricity. The discovery of a large magnetic moment in silicon may enable the use of non-magnetic and non-ferroelectric semiconductors in various multiferroic and spintronic applications.

References in corpus (6)

• Large Unidirectional Magnetoresistance in a Magnetic Topological Insulator
• Multivariable Scaling for the Anomalous Hall Effect
• Orbital magnetic moments of phonons
• Charged-phonon theory and Fano effect in the optical spectroscopy of bilayer graphene
• Spin-Hall effect and emergent antiferromagnetic phase transition in n-Si
• Giant Flexoelectricity in Bent Silicon Thinfilms