The schematic shape of a QDash. Top view (a) of the area of two width fluctuations. The cross section (b) of a QDash is a circular segment with constant height to width ratio. The symbols appearing in the figure are defined in the text.
The single carrier QDash energy spectra for holes (a) and electrons (b). The dashed line denotes the bottom of the effective potential. The presented spectra correspond to a QDash with no trapping center (λ = 0.00), a STQDash with central trapping center (*) and DTQDash (**) with two identical widenings ( ). For the case of the DTQDash the two lowest energy states are trapped within the potential fluctuations.
The absorption intensities (a) and (c) as well as the polarization properties (b) and (d) for several relevant lowest energy exciton eigenstates (the ground state Ψ0 and excited bright states Ψ2,4,6) with large enough transition probability as a function of trapping depth for a QDash with a single (a) and (b) and double (c) and (d) trapping.
The exciton energy spectrum as a function of the distance between the centers of the widenings (D 2 symmetry preserved). The linewidth of the bright states is proportional to the absorption intensity. Dark states are denoted by dashed lines.
The absorption intensities and the degree of linear polarization as a function of the distance between the centers of two identical widenings. Only the lowest energy excitonic eigenstates with highest intensities have been shown (Ψ0,4,6).
The exciton energy spectrum as a function of the value of the widening parameter λ R with constant λ L = 0.10. An anti-crossing feature can be observed at λ R = 0.10. The linewidth if proportional to the absorption intensity. The positions of widenings are xL = 68 nm and xR = 82 nm.
The absorption intensities (a) and the degree of linear polarization (b) as a function of the value of the widening parameter λ R . For λ R = 0.10 a formation of sub- (Ψ1) and super-radiant states (Ψ0) can be observed. Higher energy excitonic states (Ψ2,4,6) with highest intensities have also been shown.
The exciton energy spectrum as a function of the right widening length xR . The left widening length is set to xL = 10 nm. The linewidth if proportional to the absorption intensity.
The absorption intensities for several lowest energy exciton eigenstates (a) and the degree of linear polarization (b) as a function of the widening length xR . A strong enhancement of the ground state (Ψ0) and decline in the intensity of the first excited state (Ψ1) can be observed around the point of λ L = λ R . The intensities and the DOP of higher energy excitonic states Ψ2 and Ψ4 have been provided for reference.
The impurity of the ground state (Ψ0) and the first excited state (Ψ1) as a function of widening parameter λ R (a) and widening length xR (b).
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