Memory in quantum dot blinking br

The photoluminescence intermittency (blinking) of quantum dots is interesting because it is an easily mea-sured quantum process whose transition statistics cannot be explained by Fermi's golden rule. Commonly, thetransition statistics are power-law distributed, implying that quantum dots possess at least trivial memories. Byinvestigating the temporal correlations in the blinking data, we demonstrate with high statistical confidence thatthere is nontrivial memory between the on and off brightness duration data of blinking quantum dots. We definenontrivial memory to be statistical complexity greater than one. We show that this memory cannot be discoveredusing the transition distribution. We show by simulation that this memory does not arise from standard datamanipulations. Finally, we conclude that at least three physical mechanisms can explain the measured nontrivialmemory: (1) storage of state information in the chemical structure of a quantum dot; (2) the existence of morethan two intensity levels in a quantum dot; and (3) the overlap in the intensity distributions of the quantum dotstates, which arises from fundamental photon statistics