Field-induced control of universal fluorescence intermittency of a quantum dot light emitter

With the nonstochastic quantum mechanical study of a quantum dot light emitter, we find that fluorescence intermittency statistics are universal and insensitive to the microscopic nature of the tunneling fluctuation between quantum dot and trapping state. We also investigate the power-law exponent θ and the crossover time τ_C of the on-time (τ_on) probability P (τ_on) ∞τ _on ^-θ (for τ_on ≥τ_C) and ∞e- τ_on (for τ_on τ_C) under an optical field of given energy and strength. For easy off-resonance excitation, it is found in both numerical and analytic ways that τ_C ^-1 is proportional to the intensity of the optical field (i.e., the square of the field strength) independent of the internal parameters of a quantum dot. Furthermore, it is also found that θ=2 in the limit of vanishing field strength is the upper bound of the exponent and θ becomes less than 2 as the field strength increases.