基于光子晶体波导的量子芯片相干特性研究

Facing future application of quantum information technologies, the new pattern and integrated quantum circuits are current research fcous. In 2008, the international first quantum circuits having unit function have been successful manufactured basing on the silicon waveguide,and took the lead in realising quantum logic gate function and so on in circuits ,which open up new era of quantum information integrated. Due to the large scale of silicon waveguide (millimeter scaling in length),which result in multi-function, small integrated quantun logic circuits become a bottleneck for further development,and this science and technology difficult problem cause widespread concern of scientists at the same time.. The project aimed at achieving the quantum interference manipulation of photon in micro nano scale range basing on photonic crystal waveguide quantum circuits, combining the photonic regulate and control mechansim of photonic crystal to photon. We design theoretically the photonic crystal waveguide quantum circuits having logic function of quantum interference and phase control;We realise experimentally high efficiency directional coupler and Mach-Zehnder interferometer having path-code quantum interference by intruducing skilled micro nano fabrication technology of silicon-based material,then develop unit devices of specfic quantum logic gate.We finally obtain high-visibility and high-stability quantum circuits of photonic crystal waveguide structure, which establish theoretical and experimental basis for designing and producing of more complex all-soild quantum circuits.

面向未来量子信息技术应用，新型集成化的量子芯片是目前研究的前沿热点。国际上于2008年首次基于硅波导，研制成功具有单元功能的量子芯片，率先在芯片中实现了量子逻辑门等功能，开辟了量子信息集成化的新纪元。但由于硅波导尺度大（长度mm量级），导致多功能量子逻辑芯片的可小型集成化成为发展的一个瓶颈，也是科学家们普遍关注的科学技术难题。.本项目旨在基于光子晶体波导的量子芯片，结合光子晶体对光子的调控机理，实现在微纳尺度内对光子的量子相干操纵。理论上设计具有量子干涉、相位调控等逻辑功能的光子晶体波导量子芯片；实验上引入成熟的硅基材料微纳加工技术，实现路径编码量子干涉的高效定向耦合器和微小尺度相位可调的马赫曾德尔干涉仪，进而研制特定的量子逻辑门单元器件，对研制的光量子芯片进行量子相干特性研究，最终获得高干涉可见度，高稳定性的光子晶体波导量子芯片，为更复杂的全固态量子芯片的设计和研制奠定理论和实验基础。

本项目“基于光子晶体波导的量子芯片相干特性研究（No.61205043）"主要基于光子晶体对光的调控机理，结合成熟的硅基材料微纳加工技术，制备适用于量子相干测量的特定逻辑功能的硅基光子晶体集成器件，为更复杂的光子晶体集成器件在量子信息应用方面提供理论和实验基础。具体：1.理论上设计了光子晶体波导结构的定向耦合器和基于自准直的分束器结构，同时设计了面向量子行走的光子晶体耦合波导阵列和自准直分束器阵列结构。2. 实验上，在SOI基片上，制备了21条波导的耦合波导阵列和4*4的自准直分束器阵列结构，利用连续激光，观察到了光在光子晶体中的传输行为，并演示了光子晶体能带对光的调控特性，最终成功观察到了类单光子量子行走现象。3. 建立了波导对准耦合和光栅耦合结合的实验测试系统，同时建立了红外近场扫描探针实验测试系统。经过本项目的实施，发表论文7篇，申报发明专利3项。培养研究生3名。