Improved scalability of silicon quantum computing with ambipolar devices

量子计算具有比经典计算更有效地解决某些复杂问题的潜力，有望在医疗保健、金融、能源、通信和机器学习等领域取得重大进展。在传统半导体工业的基础上，在硅上实现量子计算机，将为以合理的成本制造可扩展的高密度设备提供一条引人注目的途径。硅中的量子比特（量子位）已经被证明使用的是被称为量子点的纳米级结构中的电子。在过去十年中，控制这些量子位的精度大大提高，目前小型系统中的最先进技术接近容错量子计算所需的阈值。虽然电子量子位可以长时间保持相干，但在可扩展的体系结构中，操作速度相对较慢。另一种类型的量子比特可以通过没有电子来实现，称为“空穴”。与电子相比，硅中的空穴量子比特可以在更快的时间尺度上进行操作，但通常不能保持长时间的相干性。因此，在选择量子位时需要权衡利弊。这项国际合作旨在开发一种混合方法，在这种方法中，两种类型的量子位可以在同一设备（双极）中实现，此外，它们之间可以交换信息。这种双极性器件可以实现“两全其美”，并将为大规模量子处理器的设计提供额外的能力和灵活性。该项目的成果将增强加拿大在量子信息领域和半导体量子计算平台发展方面的领导地位。

Quantum computation has the potential to solve certain complex problems more efficiently than classical computation, promising significant advancements in areas such as healthcare, finance, energy, communication and machine learning. Realizing a quantum computer in silicon, building on the conventional semiconductor industry, would provide a compelling pathway to manufacturing scalable, high-density devices at reasonable cost. Quantum bits (qubits) in silicon have been demonstrated using electrons confined to nanoscale structures called quantum dots. The precision of controlling these qubits has increased dramatically over the past decade, with the current state-of-the-art in small systems close to the thresholds needed for fault tolerant quantum computing. While electron qubits can remain coherent for long times, the speed of manipulation can be relatively slow in scalable architectures. Another type of qubit can be realized by the absence of an electron, known as a "hole". Hole qubits in silicon can be manipulated on faster timescales compared to electrons, but typically do not remain coherent as long. Hence, there are trade-offs associated with the choice of qubit. This international collaboration aims to develop a hybrid approach in which both types of qubit can be realized in the same device (ambipolar), and furthermore, information can be exchanged between them. Such ambipolar devices can achieve the "best of both worlds" and will lend additional power and flexibility to the design of large-scale quantum processors. The outcomes of this project will enhance Canadian leadership in the quantum information field and in the development of semiconductor quantum computing platforms.