Angular momentum-induced delays in solid-state photoemission enhanced by intra-atomic interactions

Area of Science:

• Solid-state physics
• Quantum mechanics
• Attosecond science

Background:

• Photoemission from solids is a fundamental process.
• Existing models do not fully explain observed photoemission delays.
• Attosecond time-resolved techniques offer new insights into electron dynamics.

Purpose of the Study:

• To investigate the origins of photoemission delays in solids.
• To refine theoretical models of solid-state photoemission.
• To understand the role of intra-atomic interactions and angular momentum in photoemission timing.

Main Methods:

• Utilized attosecond time-resolved photoemission spectroscopy.
• Measured relative emission delays for four photoemission channels in tungsten diselenide (WSe2).
• Developed theoretical models incorporating propagation and intra-atomic delays.

Main Results:

• Observed photoemission delays in WSe2 are explained by combined propagation and intra-atomic effects.
• Intra-atomic delays are dependent on the initial state's angular momentum.
• Photoemission events were time-ordered by increasing initial-state angular momentum.

Conclusions:

• Intra-atomic electron-electron interactions and initial state angular momentum are crucial for accurate photoemission modeling.
• The study necessitates revisions to current solid-state photoemission models.
• Attosecond spectroscopy provides critical benchmarks for advancing photoemission theories.