基于重叠栅工艺的硅量子点阵列的制备与调控

利用半导体量子点阵列结构实现近邻耦合是规模化扩展自旋量子比特的主要方案之一. 随着量子点数目的增加, 量子点阵列器件的制作工艺及参数调控均愈加复杂. 本文介绍了一种重叠栅工艺结构, 利用多层相互重叠且具有不同功能的栅极定义量子点, 制作出结构紧凑、 调控性好的量子点阵列器件, 解决了工艺扩展的难题. 此外,本文发展了一套高效可靠的调控方法, 按顺序逐个添加量子点并建立虚拟电极, 实现了对量子点参数的独立控制,并且能够高效且独立地调控各量子点中的电子数目, 克服了大规模量子点阵列中电压参数配置的困难. 这些方法为未来实现大规模自旋比特阵列提供了一种标准化的方案.

Fabrication and Tuning of Silicon Quantum Dot Array with Overlapping Gates

Utilizing semiconductor quantum dot arrays to achieve nearest-neighbor coupling is one of the main approaches for scaling up spin qubits. However, as the number of quantum dots increases, the device design, fabrication, and parameters tuning of the quantum dot array face great challenges. Here, we introduce an overlapping-gates structure, which uses multiple layers of overlapping gates to define quantum dots and provides a promising technique for quantum dots scaling. We successfully fabricate compact and well-tuned quantum dot array devices with this structure. In addition, we develop a tuning method with high efficiency and reliability, which realizes the independent control of quantum dot parameters by establishing virtual gates, and the number of electrons in each quantum dot can be efficiently and independently tuned. These methods overcome the difficulty of parameter configuration in large-scale quantum dot arrays and provide a standardized scheme for realizing large-scale spin qubit array in the future.