Optical Control of Ferroic Domain Configuration through Light Polarization’

The sensitivity of the ferroelectric domain walls to external stimuli makes them functional entities in
nanoelectronic devices. Precise control and manipulation of ferroelectric domain walls (DWs)
movement offer a new data storage principle where data is stored and processed by the DWs. The
possibility of continuous tunability of the DWs can extend the concept of binary state to multistate
switching. This makes reconfigurable ferroelectric DWs vital for the next generation of
nanoelectronics devices such as racetrack memory. The effective optical control of the domain
configuration has remained challenging and far from fully understood. I shall present my work on
effective optical control with the guided variations in the domain configurations of ferroelectric
BaTiO 3 and show that the strain field generated through the bulk photovoltaic effect plays a key role
in domain reconfiguration [1]. Furthermore, our polarized Raman mapping investigations unveiled the
existence of hidden in-plane polarized sub-domains imitating a single domain state in these BaTiO 3
crystals. These domain configurations are optically reconfigurable and can survive down to
monolayer thickness at room temperature. I will show that contrary to the present belief long-range
ferroelectric polarization is not essential for the optical control of domain wall movement. Instead,
flexoelectricity is found to be an essential ingredient for the optical control of the domain
configuration and hence, ferroelastic materials would be another possible candidate for nanoelectronic
device applications.
References:
1. Physical Review B 105 (13), 134103 (2022).
2. arXiv preprint arXiv:2207.09207 (2022).