Subnanosecond Reconfiguration of Ferroelectric Domains in Bismuth Ferrite

Domain switching is crucial for achieving desired functions in ferroic materials that are used in various applications. Fast control of domains at subnanosecond timescales remains a challenge despite its potential for high-speed operation in random access memories, photonic, and nanoelectronic devices. In our recent work [1], we show that ultrafast laser excitation can transiently melt and reconfigure ferroelectric stripe domains in multiferroic bismuth ferrite on a timescale faster than 100 ps. This dynamic behavior is visualized by a novel approach of picosecond and nanometer-resolved X-ray diffraction. In addition, we developed and used time-resolved X-ray diffuse scattering to track the transient response of the domain walls. The disordering of stripe domains arises from the screening of depolarization fields by photogenerated carriers resulting in the formation of charged domain walls which is further supported by phase field simulations. Furthermore, the recovery of disordered domains exhibits subdiffusive growth on nanosecond timescales, with a nonequilibrium domain velocity reaching up to 10 m/s. These findings present a new approach to image and manipulate ferroelectric domains on subnanosecond timescales, which can be further extended into other photoferroic systems to modulate their electronic, optical, and magnetic properties beyond GHz frequencies. This approach could pave the way for high-speed ferroelectric data storage, computing and photonic applications in a range of photoferroics, and, more broadly, defines new approaches for visualizing the non-equilibrium dynamics of heterogeneous and disordered materials.<br/><br/>[1] B. Guzelturk et al. Advanced Materials (2023) - DOI: 10.1002/adma.202306029