Multi-mode excitation drives disorder during the ultrafast melting of a C4-symmetry-broken phase.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35017507.
- Also identified by DOI 10.1038/s41467-021-27819-y and PMC identifier 8752725.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Spontaneous C<sub>4</sub>-symmetry breaking phases are ubiquitous in layered quantum materials, and often compete with other phases such as superconductivity. Preferential suppression of the symmetry broken phases by light has been used to explain non-equilibrium light induced superconductivity, metallicity, and the creation of metastable states. Key to understanding how these phases emerge is understanding how C<sub>4</sub> symmetry is restored. A leading approach is based on time-dependent Ginzburg-Landau theory, which explains the coherence response seen in many systems. However, we show that, for the case of the single layered manganite La<sub>0.5</sub>Sr<sub>1.5</sub>MnO<sub>4,</sub> the theory fails. Instead, we find an ultrafast inhomogeneous disordering transition in which the mean-field order parameter no longer reflects the atomic-scale state of the system. Our results suggest that disorder may be common to light-induced phase transitions, and methods beyond the mean-field are necessary for understanding and manipulating photoinduced phases.