Spatial coherence of electron bunches extracted from an arbitrarily shaped cold atom electron source

Area of Science:

• Atomic physics
• Electron optics
• Quantum optics

Background:

• Understanding electron beam coherence is vital for applications in microscopy and lithography.
• Cold atom electron sources offer unique properties for generating electron beams.
• Spatial coherence influences the resolution and quality of electron-based technologies.

Purpose of the Study:

• To model and measure the spatial coherence properties of electron bunches from a cold atom electron source.
• To determine the transverse spatial coherence length (lc) of these electron bunches.
• To establish a foundation for further advancements in cold atom electron source technology.

Main Methods:

• Development of a quasihomogeneous wavefield model for electron sources.
• Direct measurement of transverse spatial coherence length using electron bunch propagation.
• Utilizing a sinusoidal intensity profile generated by a spatial light modulator on an atomic excitation laser.
• Analysis of electron distribution visibility at variable spatial frequencies.

Main Results:

• A lower limit for the spatial coherence length at the source was measured.
• The measured coherence length was determined to be lc = 7.8 ± 0.9 nm.
• The study demonstrates a method for characterizing electron beam coherence.

Conclusions:

• The spatial coherence properties of cold atom electron sources can be effectively modeled and measured.
• The achieved coherence length provides a benchmark for this type of electron source.
• This research contributes to the development of advanced electron beam technologies.