论文标题
接近从纳米线量子点上激发的纳米线量子点的转换限制的光子
Approaching transform-limited photons from nanowire quantum dots excited above-band
论文作者
论文摘要
我们证明，即使采用上带上激发，从半导体量子点发出的光子也可能具有接近其变换限值值的线宽。这是通过使用嵌入自下而上的光子纳米线中的量子点来实现的，这种方法可以减轻几种潜在的机制，这些机制可能导致线宽扩展：（i）每个设备中只有一个量子点，（ii）点成核进行，而没有形成润湿层和（iii）nonan nan nan of nan nan of nan of nan of ersonic nan of nan of nan of nan of nan of nan of nan of nan of nan of nanof ersonic erson的群体。外延生长的晶体平面。使用这些结构，我们达到了2倍的线宽，转换极限，前所未有用于上段激发。我们还证明了线宽对激发能力和温度的高度非线性依赖性，可以通过独立的玻色子模型来描述，该模型考虑了变形和压电式激子 - phonon耦合。我们发现，对于足够低的激发能力和温度，观察到的过量扩展不是由声子dephasing主导的，这是一个令人惊讶的结果，考虑到以上频段激发发生的高声子占用。
We demonstrate that, even when employing above-band excitation, photons emitted from semiconductor quantum dots can have linewidths that approach their transform-limited values. This is accomplished by using quantum dots embedded in bottom-up photonic nanowires, an approach which mitigates several potential mechanisms that can result in linewidth broadening: (i) only a single quantum dot is present in each device, (ii) dot nucleation proceeds without the formation of a wetting layer, and (iii) the sidewalls of the photonic nanowire are comprised not of etched facets, but of epitaxially grown crystal planes. Using these structures we achieve linewidths of 2x the transform limit, unprecedented for above-band excitation. We also demonstrate a highly nonlinear dependence of the linewidth on both excitation power and temperature which can be described by an independent Boson model that considers both deformation and piezoelectric exciton-phonon coupling. We find that for sufficiently low excitation powers and temperatures, the observed excess broadening is not dominated by phonon dephasing, a surprising result considering the high phonon occupation that occurs with above-band excitation.
