Templated Quantum Dots and Optimized Photonic Crystal Cavities.

[摘要] One of the most exciting areas of current physics research revolves around the physical implementation of quantum computing. Proposals exist to embed quantum dots within photonic crystal cavities and couple the quantum dot states with the cavity modes. With the proper controls, it may be possible to use these systems as a basis for quantum information processing.Semiconductor quantum dots have recently attracted a great deal of research interest. Due to their macroscopic size, researchers can optically access individual dots and observe their nonclassical nature. However the applicability of quantum dots can be limited by their random size and placement using typical growth techniques. In our work we demonstrate our ability to control the spatial positioning of InAs/GaAs quantum dots though an in vacuo fabrication procedure. By characterizing their growth and optical properties, we demonstrate our ability to create optically active quantum dots and to achieve 100% site placement fidelity.Photonic crystal cavities are novel devices which enable us to tailor the optical response of a material. Improving the quality of these cavity designs can strongly influence our ability to couple them to embedded emitters, such as quantum dots. Optimizing the cavity configuration is a problem involving many variables which cannot be fully explored using traditional techniques. We employ a nature inspired search algorithm to discover novel cavity arrangements that exceed existing methods.Establishing the coupling efficiency between a quantum dot and the photonic crystal cavity surrounding it is an important step to using these as a platform for further investigations. A variety of techniques exist to demonstrate this property, each with its advantages. We explore the method of luminescence intensity autocorrelation to determine the exciton lifetime of a single quantum dot and the influence of its cavity coupling. We demonstrate this method in the Purcell regime and find the Purcell factor for a weakly coupled quantum dot.

[发布机构] University of Michigan

[效力级别] Optimized Photonic Crystal Cavities

[关键词] Templated Quantum Dots;Optimized Photonic Crystal Cavities;Physics;Science;Physics