nl1c00052_si_001.pdf (3.6 MB)
Download fileLarge Magnetic Moment in Flexoelectronic Silicon at Room Temperature
journal contribution
posted on 19.03.2021, 12:35 authored by Paul C. Lou, Anand Katailiha, Ravindra G. Bhardwaj, Ward P. Beyermann, Dominik M. Juraschek, Sandeep KumarTime-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 μB/atom in a 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 flexoelectronic polarization
instead of ferroelectricity. The discovery of a large magnetic moment
in silicon may enable the use of nonmagnetic and nonferroelectric
semiconductors in various multiferroic and spintronic applications.