Field-cycle-resolved photoionization in solids

Area of Science:

• Solid-state physics
• Quantum optics
• Ultrafast phenomena

Background:

• The Keldysh theory describes photoionization in solids under intense laser fields.
• Understanding ionization dynamics is crucial for controlling light-matter interactions.
• Previous models often assumed long laser pulses, limiting applicability to new ultrafast regimes.

Purpose of the Study:

• To generalize the Keldysh theory for photoionization in solid dielectrics.
• To develop a solution applicable to arbitrarily short driving pulses of any shape.
• To investigate ultrafast ionization dynamics within a single field cycle.

Main Methods:

• Derivation of a closed-form solution for the nonadiabatic ionization rate.
• Analysis of photoionization in transparent solids with periodic dispersion relations.
• Comparison with existing theoretical frameworks in limiting cases.

Main Results:

• A generalized theoretical framework for Keldysh photoionization is established.
• The solution captures ultrafast ionization dynamics occurring within the optical field cycle.
• The derived solution recovers the established Keldysh theory results under appropriate approximations.

Conclusions:

• The generalized theory accurately describes photoionization dynamics for ultrashort laser pulses.
• This work provides a powerful tool for studying light-matter interactions in the ultrafast regime.
• The findings have implications for controlling electron emission and material modification with intense light.