Attosecond-resolved petahertz carrier motion in semi-metallic TiS2

摘要: Knowledge about the real-time response of carriers to optical fields in solids is paramount advance information processing towards frequencies or understand bottlenecks light-matter interaction and energy harvesting. Of particular importance are semi-metals transition metal dichalcogenides due their small band gap high carrier mobility. Here, we examine opto-electronic TiS2 excitation by means attosecond soft x-ray spectroscopy at L-edges Ti 460 eV. Using weak-field infrared single-photon excitation, conditions that avoid excessive but still attain efficient injection 0.2% valence into lowest lying conduction band. We demonstrate high- mobility permits leveraging material achieve petahertz-speed control its carriers. Our results an important step understanding dynamics under field realistic for device implementation semi-metallic layered materials, thus they may lead ultrafast optically controlled field-effect devices sensors.