Abstract:

Ultrafast switching of ferroic phases is an active research area
with technological potential. Yet, some key challenges remain,
ranging from limited speeds in ferromagnets to intrinsic
volatility of switched domains owing to depolarizing fields in
ferroelectrics. Unlike these ferroic systems, ferroaxial materials
host bistable states that preserve spatial-inversion and time-
reversal symmetry and are therefore immune to depolarizing
fields but also difficult to manipulate with conventional methods.
We demonstrate photo-induced switching of ferroaxial order
by engineering an effective axial field composed of circularly
driven terahertz phonon modes. A switched ferroaxial domain
remains stable for many hours and can be reversed back with
a second terahertz pulse of opposite helicity. the effects
demonstrated in this work may lead to the development of a
robust platform for ultrafast information storage.