IBM Research-Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland.
ACS Nano. 2012 Mar 27;6(3):1979-87. doi: 10.1021/nn204447e. Epub 2012 Mar 1.
We demonstrate control and tunability of the exciton fine-structure splitting by properly engineering a nanojunction consisting of a CdSe nanocrystal core and an asymmetric rod-like CdS shell. Samples with small core and/or thick rod diameters exhibit a strongly reduced fine-structure splitting resulting from a reduced electron-hole exchange interaction. These results shed light onto the electronic configuration of such nanosystems and, apart from being of fundamental interest, could enable the use of colloidal nanocrystals as a source of entangled photons.
我们通过适当设计由 CdSe 纳米晶核和非对称棒状 CdS 壳组成的纳米结，展示了激子精细结构分裂的控制和可调性。具有小核和/或厚棒直径的样品表现出强烈降低的精细结构分裂，这是由于电子-空穴交换相互作用的减小。这些结果揭示了这种纳米系统的电子构型，除了具有基本的兴趣之外，还可以使胶体纳米晶体能够用作纠缠光子的源。
