Nature and excitations of the photo-induced hidden phase in LCMO

Determine the exact microscopic nature and elementary excitations of the long-lived photo-induced "hidden" phase that emerges in antiferromagnetic insulating La2/3Ca1/3MnO3 thin films under ultrafast photo-excitation.

Background

Epitaxially strained La2/3Ca1/3MnO3 (LCMO) can transition from an antiferromagnetic insulating state to a long-lived, photo-induced metastable state following ultrafast laser excitation. Although macroscopic switching has been reported previously, the microscopic nature and excitation spectrum of this photo-induced phase have been unclear.

This work combines in-situ transport, x-ray absorption spectroscopy, and resonant inelastic x-ray scattering to probe polarons, phonons, and orbitals in equilibrium and photo-induced states. The authors highlight that prior to their study, the exact character of the hidden phase and its excitations was largely unknown.

References

Indeed, AFI LCMO displays a long-lived photo-induced transition into a putative `hidden' phase whose exact nature and excitations are still largely unknown.

— Excitations across the equilibrium and photoinduced `hidden' states of magnetoresistive manganites  (2604.00991 - Fan et al., 1 Apr 2026) in Abstract