Paper NS-ThP9
Electron Tunneling in Weak Coupled Triple Quantum Dots: Sensitivity to Symmetry Violation

Thursday, November 13, 2014, 6:00 pm, Room Hall D

The electron localization and tunneling in the triple quantum dots (TQD) is studied in relation to their spectral properties. Modeled are lateral InAs/GaAs TQDs using single sub-band effective mass approach with the effective potential simulating the strain effect [1]. As an approximation, two-dimension quantum wells (QW) are considered. Dynamics of electron localizations in TQD over whole spectrum is studied by varying the inter-dot distances. To consider tunneling between localized-delocalized states selected was a QD pair (DQD). In isolated DQD, such tunneling goes consecutively from high energy levels to the ground state when the inter-dot distance decreases [2]. The electron spectrum is separated by three parts: localized states, delocalized states, and states with different probability for localization in the left and right QDs. The electron localization demonstrates extreme sensitivity to small variations of DQD shape, which violate Left-Right symmetry. The effect of adding third quantum dot to DQD is considered for weak coupling triple system. We show that presence of the third dot increases tunneling in weakly coupled DQDs. The star and chain configurations of TQDs are considered. The effect of violation of reflexing symmetry in TQD was studied. We found that the tunneling is highly sensitive to a small violation of the geometry symmetry.

This work is supported by the NSF (HRD-0833184) and NASA (NNX09AV07A).

[1] I. Filikhin, V. M. Suslov and B. Vlahovic, Phys. Rev. B 73, 205332 (2006).

[2] I. Filikhin, S. Matinyan and B. Vlahovic, Mathematical Modeling and Geometry, Vol. 2, No 2, 1 (2014).