Schematic plot of a double quantum dot coupled in parallel with a half-metallic ferromagnetic lead. Two excess electronic states in each dot constitutes a charge qubit.
(a) The time evolution of electron population in the dots, and (b) the coherence in the steady limit varying with flux ϕ for different bias μ F = eV. The initial temperature β−1 = k B T = 0.1Γ.
The coherence manipulation of the related phase ϕ(t) = ϕ i (mod 2π) between the two double dot states through the sequence temporal short pulses E i (t).
(a) A 3D-plot of stationary coherent magnitude of ρ12 with the temperature and the Fermi surface at μ = μ F + ε0. (b) The coherence dynamics of the double dot with a small inter-dot coupling, ε12 = 2.5%Γ. (c) The coherence dynamics and its stationary distribution deviated away from the degenerate electronic states, with energy level difference ε = ε1 − ε2 = 5%Γ. Other parameters k B T = 0.1Γ, ε0 = 2Γ, and μ F = eV = 10Γ.
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