Muñoz Roberto N, Frazer Laszlo, Yuan Gangcheng, Mulvaney Paul, Pollock Felix A, Modi Kavan
ARC Centre of Excellence in Exciton Science and School of Physics & Astronomy, Monash University, Clayton, Victoria 3800, Australia.
ARC Centre of Excellence in Exciton Science and School of Chemistry, Monash University, Clayton, VIC 3800, Australia.
Phys Rev E. 2022 Jul;106(1-1):014127. doi: 10.1103/PhysRevE.106.014127.
The photoluminescence intermittency (blinking) of quantum dots is interesting because it is an easily measured quantum process whose transition statistics cannot be explained by Fermi's golden rule. Commonly, the transition statistics are power-law distributed, implying that quantum dots possess at least trivial memories. By investigating the temporal correlations in the blinking data, we demonstrate with high statistical confidence that there is nontrivial memory between the on and off brightness duration data of blinking quantum dots. We define nontrivial memory to be statistical complexity greater than one. We show that this memory cannot be discovered using the transition distribution. We show by simulation that this memory does not arise from standard data manipulations. Finally, we conclude that at least three physical mechanisms can explain the measured nontrivial memory: (1) storage of state information in the chemical structure of a quantum dot; (2) the existence of more than two intensity levels in a quantum dot; and (3) the overlap in the intensity distributions of the quantum dot states, which arises from fundamental photon statistics.
量子点的光致发光间歇性（闪烁）很有趣，因为它是一个易于测量的量子过程，其跃迁统计不能用费米黄金定则来解释。通常，跃迁统计呈幂律分布，这意味着量子点至少具有简单的记忆。通过研究闪烁数据中的时间相关性，我们以高统计置信度证明，闪烁量子点的亮暗持续时间数据之间存在非平凡记忆。我们将非平凡记忆定义为统计复杂度大于一。我们表明，使用跃迁分布无法发现这种记忆。我们通过模拟表明，这种记忆并非源于标准的数据处理。最后，我们得出结论，至少有三种物理机制可以解释所测量到的非平凡记忆：（1）状态信息存储在量子点的化学结构中；（2）量子点中存在两个以上的强度水平；（3）量子点状态的强度分布重叠，这源于基本的光子统计。
