Oscillatory Hall effect from magnetoelectronic coupling in flexoelectronic silicon

Abstract

The magnetoelectronic coupling can be defined as cross-domain coupling between electronic and magnetic properties, where modulation in magnetic properties changes the electronic properties. In this letter, an explicit experimental evidence of magnetoelectronic coupling is presented, which is uncovered from oscillatory Hall effect response in Hall measurement. The strain gradient in a MgO (1.8 nm)/p-Si (~400 nm) freestanding sample leads to transfer of electrons (~5X10^18 cm^-3) from valence to conduction band due to flexoelectronic charge separation in the p-Si layer. The resulting flexoelectronic polarization gives rise to temporal magnetic moment from dynamical multiferroicity. The external magnetic field changes the net temporal magnetic moment, which causes modulations in charge carrier concentration and oscillatory Hall effect. The period of oscillatory Hall response is 1.12 T, which is attributed to the magnitude of temporal magnetic moment. The discovery of oscillatory Hall effect adds a new member to the family of Hall effects.