Hole spins in an InAs/GaAs quantum dot molecule subject to lateral electric fields

• Published in: Physical review. B Vol. 93; no. 24
• Main Authors: Ma, Xiangyu, Bryant, Garnett W, Doty, Matthew F
• Format: Journal Article
• Language: English
• Published: United States 01.01.2016
• ISSN: 2469-9950
• DOI: 10.1103/physrevb.93.245402

There has been tremendous progress in manipulating electron and hole-spin states in quantum dots or quantum dot molecules (QDMs) with growth-direction (vertical) electric fields and optical excitations. However, the response of carriers in QDMs to an in-plane (lateral) electric field remains largely unexplored. We computationally explore spin-mixing interactions in the molecular states of single holes confined in vertically stacked InAs/GaAs QDMs using atomistic tight-binding simulations. We systematically investigate QDMs with different geometric structure parameters and local piezoelectric fields. We observe both a relatively large Stark shift and a change in the Zeeman splitting as the magnitude of the lateral electric field increases. Most importantly, we observe that lateral electric fields induce hole-spin mixing with a magnitude that increases with increasing lateral electric field over a moderate range. These results suggest that applied lateral electric fields could be used to fine tune and manipulate, , the energy levels and spin properties of single holes confined in QDMs.