Ultrafast creation of a light-induced semimetallic state in strongly excited 1T-TiSe 2

• DOI: 10.1126/sciadv.adl4481
• Publication Date: 2024-05-10T17:58:45Z
• Authors: Maximilian Huber; Yi Lin; Giovanni Marini; Luca Moreschini; Chris Jozwiak; Aaron Bostwick; Matteo Calandra; Alessandra Lanzara
• Keywords: Quantum Physics; Condensed Matter - Materials Science; MSD-General; Condensed Matter - Mesoscale and Nanoscale Physics; Chemical Sciences; Physical Sciences; MSD-Ultrafast MS; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; Physical and Materials Sciences

Screening, a ubiquitous phenomenon associated with the shielding of electric fields by surrounding charges, has been widely adopted as means to modify material’s properties. While most studies have relied on static changes screening through doping or gating thus far, here we demonstrate that can also drive onset distinct quantum states ultrafast timescale. By using time- and angle-resolved photoemission spectroscopy, show intense optical excitation 1T-TiSe 2 , prototypical charge density wave material, almost instantly from gapped into semimetallic state. systematically comparing in band structure over time strength theoretical calculations, find appearance this state is likely caused dramatic reduction length. In summary, work showcases how enables screening-driven design nonequilibrium phase TiSe possibly providing general pathway highly screened phases other strongly correlated materials.