Quantum Phenomena in Nanomaterials: Coherent Superpositions of Fine Structure States in CdSe Nanocrystals at Room Temperature

One of the most recent developments at the forefront of nanotechnology is the attempt to exploit quantum phenomena in nanometer scale materials, exploring novel applications of quantum effects. An effective exploitation of quantum phenomena must necessarily pass through a deep understanding of how to generate, manipulate, and characterize coherent superposition of quantum states in the nanosystems. However, despite the lively interest in this topic, the study of coherent effects in nanomaterials still represents relatively unexplored territory. Here we report an investigation on the ultrafast coherent dynamics of colloidal CdSe quantum dots (QDs) by the mean of two- dimensional electronic spectroscopy (2DES). The time evolution of specific coherent superpositions of fine structure levels in these nanomaterials is clearly demonstrated. The obtained results represent an important step forward toward a deeper understanding of quantum properties of nanomaterials.