Electrical manipulation of an electronic two-state system in Ge quantum dots

Pryor, C. E.; Flatté, M. E.; Levy, J.
December 2009
Applied Physics Letters;12/7/2009, Vol. 95 Issue 23, p232103
Academic Journal
We calculate that the electronic states of strained self-assembled germanium quantum dots embedded in silicon provide a convenient two-state system for electrical control. An electronic state localized at the apex of the quantum dot is nearly degenerate with a state localized at the base of the quantum dot. Small electric fields shift the electronic ground state from apex-localized to base-localized, which permits sensitive tuning of the electronic, optical, and magnetic properties of the dot. As one example, we describe how spin-spin coupling between two germanium quantum dots can be controlled very sensitively by shifting the individual dot’s electronic ground state between apex and base.


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