Attosecond Electron Localization and Screening Dynamics in Metals

A high degree of electron localization on the d-orbitals of transition metals and their compounds provides a lever to efficiently control their properties with light. For example, light absorption in VO2 may result in an ultrafast electronic phase transition from a dielectric into a metallic state [1]. The essential timescale of electronic phase transitions is connected to the screening dynamics, which typically belongs to the attosecond domain. It is followed by femtosecond electron-electron thermalization, which may blur the initial imprints of screening-induced charge re-distribution. Here we show that the properties of transition metals could in principle be manipulated much faster than the electron thermalization timescale and even faster than the optical cycle.