Optically excited quantum materials exhibit nonequilibrium states with remarkable emergent properties, but these phenomena are usually transient, decaying on picosecond timescales and limiting practical applications. Advancing the design and control of nonequilibrium phases requires the development of targeted strategies to achieve long-lived, metastable phases. Here, we report the discovery of symmetry-protected electronic metastability in the model cuprate ladder Sr14Cu24O41. Using femtosecond resonant x-ray scattering and spectroscopy, we show that this metastability is driven by a transfer of holes from chain-like charge reservoirs into the ladders. This ultrafast charge redistribution arises from the optical dressing and activation of a hopping pathway that is forbidden by symmetry at equilibrium. Relaxation back to the ground state is hence suppressed after the pump coherence dissipates. Our findings highlight how dressing materials with electromagnetic fields can dynamically activate terms in the electronic Hamiltonian, and provide a rational design strategy for nonequilibrium phases of matter.
@article{arxiv.2506.03040,
title = {Symmetry-protected electronic metastability in an optically driven cuprate ladder},
author = {Hari Padma and Filippo Glerean and Sophia F. R. TenHuisen and Zecheng Shen and Haoxin Wang and Luogen Xu and Joshua D. Elliott and Christopher C. Homes and Elizabeth Skoropata and Hiroki Ueda and Biaolong Liu and Eugenio Paris and Arnau Romaguera and Byungjune Lee and Wei He and Yu Wang and Seng Huat Lee and Hyeongi Choi and Sang-Youn Park and Zhiqiang Mao and Matteo Calandra and Hoyoung Jang and Elia Razzoli and Mark P. M. Dean and Yao Wang and Matteo Mitrano},
journal= {arXiv preprint arXiv:2506.03040},
year = {2026}
}