Multidimensional high-harmonic echo spectroscopy: Resolving coherent electron dynamics in the EUV regime.

Area of Science:

• Quantum Dynamics
• Spectroscopy
• Strong-Field Physics

Background:

• Observing coherent electron dynamics is crucial for understanding molecular processes.
• Standard spectroscopic techniques have limitations in resolving ultrafast electron motion over broad energy ranges.

Purpose of the Study:

• To theoretically propose a novel multidimensional high-harmonic echo spectroscopy technique.
• To resolve coherent electron dynamics spanning multiple electronvolts with high temporal resolution.

Main Methods:

• Utilizing strong optical fields and a semi-perturbative approach.
• Employing phase-matched, well-separated few-cycle strong infrared laser pulses.
• Analyzing high harmonic echo signals generated from coherent valence electron dynamics.

Main Results:

• The proposed technique can describe coherent valence electron dynamics driven by laser pulses.
• It allows direct observation of molecular dynamics via high harmonic echo.
• Simulations demonstrate ultrafast valence electron dynamics captured with femtosecond resolution.

Conclusions:

• Multidimensional high-harmonic echo spectroscopy is a promising tool for studying ultrafast electron dynamics.
• The technique reveals novel ultra-delayed partial rephasing echoes.
• It offers a new pathway for high-resolution investigation of molecular electronic behavior.