Picosecond coherent electron motion in a silicon single-electron source

Area of Science:

• Quantum technology
• Condensed matter physics
• Ultrafast phenomena

Background:

• Understanding ultrafast coherent electron dynamics is crucial for quantum technologies like single-electron sources and qubit control.
• Current experimental bandwidths limit the observation of internal dynamics in submicrometre devices.
• Existing detection methods lack time-resolved capabilities for these fast dynamics.

Purpose of the Study:

• To theoretically and experimentally demonstrate a method for observing internal dynamics in submicrometre devices.
• To achieve time-resolved detection of electron motion within a silicon single-electron source.
• To investigate quantum coherent oscillations at high frequencies.

Main Methods:

• Utilized a silicon single-electron source with a dynamic quantum dot.
• Employed a resonant level as a detector for time-resolved measurements.
• Performed theoretical simulations with realistic parameters alongside experimental validation.
• Achieved picosecond resolution in detecting electron dynamics.

Main Results:

• Successfully observed internal dynamics in the silicon single-electron source.
• Demonstrated quantum coherent spatial oscillations of an electron wave packet at approximately 250 GHz.
• Validated experimental findings through simulations, confirming the 250 GHz oscillation frequency.
• Operated the experiment at 4.2 K.

Conclusions:

• The developed technique allows for effective time-resolved observation of internal dynamics in submicrometre devices.
• This method overcomes the limitations of current experimental bandwidths for studying ultrafast electron motion.
• Future applications include detecting fast dynamics in cavities, controlling non-adiabatic excitations, and engineering single-electron sources for advanced quantum technologies.