Strong Field Theories beyond Dipole Approximations in Nonrelativistic Regimes

Area of Science:

• Quantum mechanics
• Strong field physics
• Laser-driven electron dynamics

Background:

• The dipole approximation is commonly used for laser-driven electron dynamics.
• However, nondipole effects become significant in certain laser regimes, limiting the accuracy of the dipole approximation.

Purpose of the Study:

• To develop a strong field theory beyond the dipole approximation for nonrelativistic electron dynamics.
• To investigate nondipole effects in multiphoton and tunneling ionization.
• To analyze the influence of laser parameters and Coulomb interaction on electron momentum.

Main Methods:

• Derivation of exact nondipole Volkov solutions to the Schrödinger and Pauli equations.
• Construction of a strong field theory incorporating nondipole effects.
• Application of the theory to study momentum partition laws in ionization processes.

Main Results:

• The theory accurately describes nondipole effects in nonrelativistic laser-driven electron dynamics.
• The interplay between laser fields and Coulomb action can reverse photoelectron momentum.
• Magnetic-spin coupling has negligible observable effects on photoelectron momentum distribution.
• The developed theory extends the applicability to short wavelength and mid-infrared laser regimes.

Conclusions:

• The new theory provides a robust framework for understanding electron dynamics beyond the dipole approximation.
• It is essential for accurately modeling phenomena where nondipole effects are prominent.
• The findings are crucial for research in attosecond science and high-intensity laser-matter interactions.