University of Oxford - Equipment Account

在人类历史的最后半个世纪，随着计算机、高速通信网络和互联网的兴起，我们在处理和传播信息的能力上发生了令人难以置信的革命。进展速度仍然非常快，但随着处理设备的尺寸缩小到接近单个原子的规模，一个重大挑战即将到来。在如此微小的长度尺度上，控制电子设备运行的物理学从根本上改变，以遵守量子力学定律，计算机处理器不再能以今天的传统方式运行。这一即将到来的前景既是挑战，也是机遇。现在理论上已经知道量子力学实际上可以用来以“经典”系统不可能的方式进行计算和通信，并且现在正在许多科学学科中进行大量的研究工作，以实现这种量子通信和计算。在未来的量子电子芯片上用作量子比特（qubit）的各种有希望的候选系统将被汇集在一起，并以真正的量子相干方式进行研究。由超导电路制成的静态量子比特，以及被困在半导体芯片上的岛屿中的电子，将耦合到电子芯片上以光量子（光子）和振动运动量子（声子）形式的“飞行”量子比特，这些量子被冷却到接近绝对零度的最低量子机械能态。该研究将解决信息的脆弱量子性质在这样的系统中可以持续多久的关键问题，如何使不同的系统相互作用和交换量子信息，以及如何将它们聚集在一起，最终形成未来量子计算机的基本构建模块。如量子逻辑门和量子存储器。研究的一个特别重点是探索称为腔QED的系统的潜力，通过将光捕获在形成腔的镜子之间来增强光（或静态量子比特）和光（或飞行量子比特）。这样的系统可以观察到原子/量子比特与光之间的能量或信息交换，其速率比自由空间高得多。在这个特定的项目中，这种情况是通过在电子芯片表面捕获微波频率光子或声子来实现的，静态量子比特在芯片腔体内制造。这种用于腔QED和量子计算的架构被认为是非常有前途的，因为可以使用当今存在的传统处理器制造技术将其扩展到更大数量的量子位。

In the last half century of human history we have seen an incredible revolution in our ability to process and disseminate information, with the rise of computers, high speed communication networks, and the internet. The pace of progress is still extremely high, but a major challenge is on the horizon, as the size of processing devices shrinks to approach the scale of single atoms. At such tiny length scales, the physics governing the operation of electronic devices changes fundamentally to obey the laws of quantum mechanics, and computer processors could no longer operate in the conventional way that they do today. This approaching horizon is both a challenge and an opportunity. It has now long been known theoretically that quantum mechanics can in fact be used to carry out computing and communication in ways that are impossible with 'classical' systems, and a large research effort is now underway across many scientific disciplines to realize such quantum communication and computation in a practical way.In this fellowship, a variety of promising candidate systems for use as quantum bits (qubits) on future quantum electronic chips will be brought together and investigated in a truly quantum coherent manner. Static qubits made from superconducting electric circuits, and electrons trapped in islands on semiconductor chips will be coupled to 'flying' qubits in the form of quanta of light (photons) and quanta of vibrational motion (phonons) on electronic chips cooled to their lowest quantum mechanical energy state at close to absolute zero. The research will address key questions of how long the fragile quantum nature of information can last in such systems, how the different systems can be made to interact and exchange quantum information, and how they can be brought together to ultimately form the basic building blocks of future quantum computers, such as quantum logic gates and quantum memories.A particular focus of the research is to explore the potential of a system known as cavity QED in which the interaction between atoms (or static qubits) and light (or flying qubits) is enhanced by trapping the light between mirrors that form a cavity. Such a system makes it possible to observe the exchange of energy or information between the atoms/qubits and the light at a much higher rate than in free space. In this particular project, this scenario is realized with microwave frequency photons or phonons trapped on the surface of an electronic chip, with static qubits fabricated in place inside the on-chip cavities. This architecture for cavity QED, and for quantum computing, is thought to be highly promising since scaling it up to larger numbers of qubits may be achieved using conventional processor fabrication techniques that exist today.