An exchange-coupled donor molecule in silicon.

Area of Science:

• Solid State Physics
• Quantum Computing
• Materials Science

Background:

• Understanding donor pairs in silicon is key for quantum technologies.
• Atomic orbital hybridization impacts electronic properties.
• Accurate modeling is needed for device optimization.

Purpose of the Study:

• To experimentally and theoretically investigate the energy spectrum and exchange coupling of isolated donor pairs in silicon nanotransistors.
• To explore the effects of molecular hybridization on electron binding and charging energies.
• To validate a theoretical model against experimental data.

Main Methods:

• Combined experimental and theoretical approach.
• Utilized a silicon nanotransistor platform.
• Employed a hydrogen molecule-like model with multivalley central-cell corrected effective mass theory and full configuration interaction for the 2-electron spectrum.

Main Results:

• Observed enhanced one- and two-electron binding energies and charging energy compared to single donors.
• Demonstrated molecular hybridization of atomic orbitals in the donor pair.
• Achieved excellent agreement between the theoretical model and experimental data for an arsenic diatomic molecule.

Conclusions:

• Isolated donor pairs in silicon nanotransistors exhibit enhanced binding energies due to molecular hybridization.
• The developed theoretical model accurately predicts the behavior of donor pairs.
• These findings support the development of advanced quantum electronic devices.