Characterizing Sub-Cycle Electron Dynamics of Polar Molecules by Asymmetry in Photoelectron Momentum Distributions

Abstract

Strong-field ionization of polar molecules contains rich dynamical processes such as tunneling, excitation, and Stark shift. These processes occur on a sub-cycle time scale and are difficult to distinguish in ultrafast measurements. Here, with a developed strong-field model considering effects of both Coulomb and permanent dipole, we show that photoelectron momentum distributions (PMDs) in orthogonal two-color laser fields can be utilized to resolve these processes with attosecond-scale resolution. A feature quantity related to the asymmetry in PMDs is obtained, with which the complex electron dynamics of polar molecules in each half laser cycle is characterized and the subtle time difference when electrons escaping from different sides of the polar molecule is identified.

arXiv comment6 pages, 4 figures

References in corpus (7)

• Low-Energy Structures in Strong Field Ionization Revealed by Quantum Orbits
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• Laser-sub-cycle two-dimensional electron momentum mapping using orthogonal two-color fields
• Heteronuclear Limit of Strong-Field Ionization: Fragmentation of HeH${}^{+}$ by Intense Ultrashort Laser Pulses
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Cited by in corpus (3)

• Roles of laser ellipticity in attoclock
• Measuring Coulomb-Induced Ionization Time Lag with a Calibrated Attoclock
• Strong-field response time and its implications on attosecond measurement