Sukriti Mantri, University of Arkansas
Magnetic and polar vortices hold tremendous power to revolutionize memory devices. Formation of magnetic vortices in magnetic systems and polar vortices in ferroic films have already been shown. However, unlike magnetic vortices, controlled motion of the polar vortex has not been achieved yet.
Here, we show electric-field controlled – reversible and repeatable motion of spontaneously created polar vortex across the thickness of a (001)-oriented epitaxially-strained BiFeO3 thin films, using Monte Carlo simulations governed by a first principles-based effective Hamiltonian.
When electric field is below a critical value, the vortex moves reversibly and gradually up and down across the film-thickness, while when the field is above a critical value, the vortex moves reversibly from bottom of thin-film straight to top and back under alternating positive and negative fields. These field-controlled mobile vortices are shown to be chiral and have topological charge corresponding to a meron. With respect to memory applications, these non-volatile chiral and topological vortices represent memory-bit states. These electric field-controlled vortex motions can provide inspiration for the future of ferroelectrics-based vortex memory devices.
About the presenter
Sukriti obtained her PhD from UNSW on ferroic domain continuity across grain boundaries. She’s interested in the material properties across length scales.
Her current work with CI Nagy Valanoor and AI Laurent Bellaiche includes using x-ray and neutron diffraction techniques to predict the planar interfaces in Relaxors, the interaction of grain boundary and planar defects, existence, response and dynamics of polar vortices and other interesting topological structures in ferroic thin films. This work fits in the Centre’s Research theme 1: topological materials.