Fig. 4: Optical switching of the anomalous polarization in AlOx/SrTiO3 at 10 K.
From: Non-collinear and asymmetric polar moments at back-gated SrTiO3 interfaces
a Infrared spectra showing that the pronounced R-mode spitting at −8 kV/cm (cyan) can be erased by UV illumination (violet) and is only partially restored after the illumination (orange). The original R-mode splitting is restored after a field cycle to +8 kV/cm (red) and back to −8 kV/cm (blue). b Infrared spectra at 0 V showing that the remnant R-mode splitting (green) is erased by the UV light (violet) even after it has been turned off again (brown). c, d Corresponding infrared spectra of the polarization-induced TO mode at the LO4 edge. Shown are the difference spectra of the ellipsometric angle Ψ with respect to the pristine state at 0 V, i.e. ΔΨ = Ψexp – Ψ0V, pristine. The data are smoothened with a FFT filter.
