Coulomb Effects on time-trajectory-resolved high-order harmonic generation

Abstract

We study the effect of Coulomb potential on high-order harmonic generation (HHG) numerically and analytically. We focus on the influence of Coulomb potential on emission times of HHG associated with specific electron trajectories. By using a numerical procedure based on numerical solution of time-dependent Schrödinger equation (TDSE) in three dimensions, we extract the HHG emission times both for long and short electron trajectories. We compare TDSE predictions with those of a Coulomb-modified model arising from strong-field approximation (SFA). We show that the Coulomb effect induces earlier HHG emission times than those predicted by the general SFA model without considering the Coulomb potential. In particular, this effect influences differently on long and short electron trajectories and is more remarkable for low-energy harmonics than high ones. It also changes the HHG amplitudes for long and short electron trajectories. We validate our discussions with diverse laser parameters and forms of Coulomb potential. Our results strongly support a four-step model of HHG.

References in corpus (6)

• Low-Energy Structures in Strong Field Ionization Revealed by Quantum Orbits
• Ionization Time and Exit Momentum in Strong-Field Tunnel Ionization
• Role of Excited States In High-order Harmonic Generation
• Coulomb time delays in high harmonic generation
• Tracing origins of asymmetric momentum distribution for polar molecules in strong linearly-polarized laser fields
• Strong-field double ionization dynamics of vibrating HeH${}^{+}$ versus HeT${}^{+}$

Cited by in corpus (1)

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