Gigahertz single-trap electron pumps in silicon

Area of Science:

• Solid State Physics
• Quantum Electronics
• Nanotechnology

Background:

• Single-electron manipulation is fundamental for advanced electronics and metrology.
• High-frequency, high-accuracy single-electron pumps are vital for practical current standards.
• Localized semiconductor states offer potential for accurate electron pumping due to large activation energies.

Purpose of the Study:

• To investigate the mechanism of localized-state-mediated single-electron pumps for high-frequency, high-accuracy operation.
• To demonstrate a functional single-electron pump utilizing a single-trap level in silicon nanotransistors.

Main Methods:

• Fabrication of silicon nanotransistors with a single-trap level.
• Utilizing gate control to manipulate electron capture and emission rates.
• Operating the device at cryogenic temperatures (17 K) and high frequencies (3 GHz).

Main Results:

• Demonstrated a single-electron pump based on a single-trap level with an activation energy of tens of millielectron volts.
• Achieved pump operation at 3 GHz with an accuracy better than 10⁻³.
• Showed that electric fields at the trap level reduce capture and emission times to below 25 picoseconds.

Conclusions:

• Localized states in semiconductors are viable for high-accuracy, high-frequency single-electron pumping.
• Gate-controlled manipulation of capture/emission rates is effective for pump operation.
• This technology advances the development of single-electron-based information processors and electrical standards.