Creating flat-band materials through light-induced chemical reactions

Materials with flat bands attract significant attention as potential platforms for strongly correlated electron phenomena, including unconventional superconductivity. However, despite extensive research in this field, a stable bulk material with isolated, strongly correlated electrons in flat bands near the Fermi level has yet to be identified. We postulate that materials with flat bands are metastable and that their synthesis poses a challenge for traditional solid-state synthesis methods. In this work, we explore ultrafast photochemical reactions, an extension of light-induced phase transitions, as a means of reaching new metastable materials with desired properties.

We computationally investigate the possibility of inducing an ultrafast reaction in crystalline, semiconducting materials with the general formula K2X2 (X = S, Se, Te) to produce metastable metallic materials with linear chains. We find that an application of ultrashort laser pulses can induce this transformation, leading to a desired metastable product. The results presented in this work define a new path towards the discovery and synthesis of bulk flat-band materials.