Non-ergodicity of Blinking Quantum Dots and Other Lévy Walk Processes
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)Abstract
Quantum dots (QD) interacting with a continuous wave laser field,
exhibit intermittent blinking, where the QD turns from
state on where it emits many photons to state off and vice versa.
We investigate the non-ergodic properties of blinking
QDs modeled by a Levy-walk stochastic
process 1. Using a non-ergodic mean field approach we calculate the
distribution functions of the time averaged intensity correlation function.
We show that these distributions are not delta peaked on the
ensemble average correlation function values;
instead they are W or U shaped and related to the arcsine law.
Physical origin of the blinking is explained
based on a diffusion model and comparison between experiment
and theory is made 2. Beyond blinking nano-
crystals our results describe ergodicity breaking in systems modeled by
Levy walks, for example, certain
types of chaotic maps, and spin dynamics to name a few.
1) G. Margolin, E. Barkai Phys. Rev. Letters 94 080601 (2005)\\
2) G. Margolin, V. Protasenko, M. Kuno,E. Barkai
Advances in Chemical Physics 133 327 (2006).