Strong electron-electron interactions in Si/SiGe quantum dots

Understand

Interactions between electrons can strongly affect the shape and functionality of multi-electron quantum dots.

• The resulting charge distributions can be localized, as in the case of Wigner molecules, with consequences for the energy spectrum and tunneling to states outside the dot.
• The situation is even more complicated for silicon dots, due to the interplay between valley, orbital, and interaction energy scales.
• Here, we study two-electron wavefunctions in electrostatically confined quantum dots formed in a SiGe/Si/SiGe quantum well at zero magnetic field, using a combination of tight-binding and full-configuration-interaction (FCI) methods, and taking into account atomic-scale disorder at the quantum well interface.