Ultrafast electron dynamics in phenylalanine initiated by attosecond pulses

Abstract

El acceso a la versión del editor puede requerir la suscripción del recurso Access to the published version may require subscription Ultrafast Electron Dynamics in Phenylalanine Initiated by Attosecond Pulses Abstract:In the last decade attosecond technology has opened up the investigation of ultrafast electronic processes in atoms, simple molecules and solids. Here we report the application of isolated attosecond pulses to prompt ionization of the amino acid phenylalanine, and the subsequent detection of ultrafast dynamics on a sub-4.5-fs temporal scale, which is shorter than the vibrational response of the molecule. The ability to initiate and observe such electronic dynamics in polyatomic molecules represents a crucial step forward in attosecond science, which is progressively moving towards the investigation of more and more complex systems.One Sentence Summary: Ultrafast electron dynamics on a sub-4.5-fs temporal scale, which precedes any nuclear motion, is initiated in an amino acid by attosecond pulses.

Using quantum dynamics simulations to follow the competition between charge migration and charge transfer in polyatomic molecules

“…the nature and timescale of the transition between the two regimes. This transition and subsequent time-evolution is important in understanding processes such as the fragmentation of peptides after ionisation [6,7,8].…”

Probing the role of excited states in ionization of acetylene

“…Studying attosecond processes in molecules involves initiating a reaction by driving electrons far from equilibrium using a pump laser: one of the most widely used techniques is to ionize the molecule. The subsequent evolution of the electronic dynamics is followed by probing the system at later times using methods such as high-harmonic spectroscopy and photoelectron spectroscopy [2,[6][7][8]. Unravelling these dynamical processes presents a huge challenge due to the number of potential pathways that exist as well as the inherent difficulties of relating the initial and intermediate states to the photo-products produced.…”

“…In order to overcome these shortcomings, a range of techniques, based on ab initio methods, have been developed. Pioneering ab initio studies using density functional theory (DFT) [6,15,16,31] and configuration interaction (CI) methods [32] have been used to study electron migration in molecules following sudden removal of an electron and have observed charge oscillations along the full length of the molecule with a period of several femtoseconds. The drawback of these approaches is that the initial pumping of the molecule by a laser pulse is not described.…”

Spatial and temporal control of populations, branching ratios, and electronic coherences in LiH by a single one-cycle infrared pulse

“…Electron localization has been probed in diatomic cations [8][9][10][11][12] and larger systems [13][14][15][16] using pump-probe schemes involving atto and fs optical pulses. In these experiments the molecule is locally ionized by the pump which creates a non stationary state in the cation.…”