Phase-dependent excitation and ionization in the multiphoton ionization regime

Area of Science:

• Atomic Physics
• Quantum Optics
• Laser-Matter Interactions

Background:

• Few-cycle laser pulses offer unique control over light-matter interactions.
• The carrier envelope phase (CEP) is a critical parameter in ultrafast laser science.
• Multiphoton ionization is a fundamental process in strong-field physics.

Purpose of the Study:

• To theoretically investigate the dependence of atomic excitation and ionization on the CEP.
• To explore these dependencies in the multiphoton ionization regime using few-cycle laser pulses.
• To analyze the behavior of hydrogen atoms under specific laser conditions.

Main Methods:

• Solving the 3D time-dependent Schrödinger equation.
• Theoretical modeling of atomic response to intense laser fields.
• Simulations for hydrogen atom under few-cycle laser pulse interaction.

Main Results:

• A strong dependence of atomic excitation and ionization on the CEP was found.
• This phase dependence is evident in total ionization yields.
• Bound-state populations also exhibit significant phase dependence, even in weak laser intensity regimes.

Conclusions:

• The carrier envelope phase is a crucial factor governing atomic ionization and excitation dynamics.
• Understanding CEP effects is vital for controlling light-matter interactions with few-cycle pulses.
• Theoretical predictions highlight the sensitivity of atomic states to laser pulse characteristics.