Department of Chemistry and Centre for Quantum Information and Quantum Control, University of Toronto, 80 Saint George Street, Toronto, Ontario, M5S 3H6 Canada.
Nano Lett. 2012 Feb 8;12(2):880-6. doi: 10.1021/nl2039502. Epub 2012 Jan 4.
Coherent superpositions among eigenstates are of interest in fields as diverse as photosynthesis and quantum computation. In this report, we used two-dimensional electronic spectroscopy (2D ES) to measure the decoherence time of a superposition of the two lowest-energy excitons in colloidal CdSe nanocrystals (cubic phase) in solution at room temperature. In the electron-hole representation, the quantum coherence is, remarkably, a twelve-particle correlation. By comparing the measured 2D ES to simulations, we also explored the effects of inhomogeneous broadening and examined the spectroscopic signatures of biexcitons.
相干叠加在各个领域都很重要，如光合作用和量子计算。在本报告中，我们使用二维电子光谱（2D ES）来测量胶体 CdSe 纳米晶体（立方相）在溶液中室温下两个最低能激子叠加的退相干时间。在电子-空穴表示中，量子相干性是一个十二粒子相关。通过比较测量的 2D ES 与模拟，我们还研究了非均匀展宽的影响，并研究了双激子的光谱特征。
