Condensed Matter (Oct 2023)
Ultrafast Pump–Probe Spectroscopy in Organic Dirac Electron Candidate <i>α</i>-(BETS)<sub>2</sub>I<sub>3</sub>
Abstract
Photo-induced carrier dynamics were measured in the organic Dirac electron candidate α-(BETS)2I3 to investigate why resistivity increases below TMI = 50 K. We found a change in carrier dynamics due to an insulating gap formation below T′ = 50 K. On the other hand, the relaxation time and polarization anisotropy of the observed dynamics differ from those in the charge-ordering (CO) state of the isostructural salt α-(ET)2I3. Based on the difference, it can be concluded that the insulating phase has a different origin than the CO state.
Keywords