Coherent quantum information platform with spin-orbit coupling in silicon

量子计算机和量子模拟器有可能在机器学习、优化以及材料和药物模拟等领域执行现代计算机上不可能完成的计算任务。实现这种潜力被认为是科学界的一个巨大挑战，因为它需要对大型量子系统进行精确的工程和控制，同时避免破坏量子效应和破坏计算的退相干。然而，目前没有一个量子比特（qubit），这种系统的构建块，具有实现这一目标所需的特性。 我的研究计划的目的是使用硅技术来演示一个量子模拟器，它可以为量子凝聚态物理学中的现象提供新的见解，以及一个原型通用量子计算机，它克服了基于自旋的量子计算的主要障碍，在同一芯片上互连许多量子位而不牺牲可制造性。我的实验计划将采用超纯硅材料，创新的低温高磁场实验，并与可控量子系统的领先理论专家合作。 为了实现第一个里程碑，将追求硅中基于自旋的量子位之间的远程电介导耦合。这将利用我最近的发现，即自旋量子位可以具有自旋轨道耦合，从而实现电量子位耦合，同时保持极长的相干时间，这些特性以前被认为是不兼容的。关键是使用空穴自旋，其中总角动量（而不是自旋）是量子化的。 电路和/或谐振器将用于控制和互连量子比特，以演示电介导的纠缠逻辑门并优化其精度，这是该领域的一项重大成就。 第二个里程碑将是开发一个基于自旋量子比特的量子模拟器，以揭示凝聚态物理学中强相关费米子的问题，该问题很难用经典方法模拟，也很难用其他系统模拟量子力学。这将利用我最近的发现，即自旋量子比特模拟费米行为，使它们特别适合模拟包括非常规超导性在内的各种现象。 具有短程相互作用的更大量子位阵列将使第一个真正的费米量子模拟器成为可能，而长程电相互作用可以为模拟更难以捉摸的现象开辟一条途径。 成功实现这些目标可以推动加拿大在建立大规模量子技术的国际竞赛中处于领先地位，并从基于量子物理的第二次信息革命的预期社会经济效益中获得很大份额。

Quantum computers and quantum simulators have the potential to perform computational tasks that are impossible on modern computers in areas like machine learning, optimisation, and simulation of materials and drugs. Realising this potential is considered a grand challenge in the sciences because it requires precise engineering and control of a large quantum system, while avoiding decoherence that destroys quantum effects and corrupts the computation. However, no single quantum bit (qubit), the building block of such systems, currently has the characteristics required to achieve this goal. The aim of my research program is to use silicon technology to demonstrate a quantum simulator that can shed new light on phenomena in quantum condensed matter physics, and a prototype general purpose quantum computer that overcomes the main obstacle for spin-based quantum computing, interconnecting many qubits on the same chip without sacrificing manufacturability. My experimental program will employ ultra-pure silicon materials, innovative low-temperature high magnetic field experiments, and collaboration with leading theoretical experts on controllable quantum systems. To achieve the first milestone, long-range electrically mediated coupling between spin-based qubits in silicon will be pursued. This will leverage my recent discovery that spin qubits can possess spin-orbit coupling enabling electrical qubit coupling while maintaining extremely long coherence times, characteristics previously thought to be incompatible. The key is to use hole spins where total angular momentum (not spin) is quantized. Electrical circuits and/or resonators will be employed control and interconnect the quantum bits to demonstrate electrically mediated entangling logic gates and optimise their accuracy, a major achievement for the field. The second milestone will be to develop a quantum simulator based on spin qubits to shed new light on the problem strongly correlated fermions in condensed matter physics that is hard to simulate classically, and hard to simulate quantum mechanically with other systems. This will leverage my recent discovery that spin qubits emulate the Fermionic behaviour making them uniquely suited to simulate a wide range of phenomena including unconventional superconductivity. Larger arrays of qubits with short range interactions will enable the first true Fermionic quantum simulators, while the long-range electrical interactions could open a pathway to simulate even more elusive phenomena. Successfully achieving these goals could propel Canada to lead the international race to build large-scale quantum technologies, and to reap a great share of the expected socio-economic benefits of a second information revolution based on quantum physics.