Superconducting NbSi Quantum Phase-Slip Nanowire Devices for Electronics

我们将开发超导设备，使高科技电子产品的应用，基于量子力学现象称为量子相位滑移（QPS）。整个提案都是关于在超导纳米线中发展这种迄今为止还没有发展的量子力学表现。发展将是我们对物理学的基本理解，通过最近提出的理论的实验测试，并通过开发在未来纳米级应用中有用的电路元件走向具体应用。未来应用的一个特定领域是作为量子比特技术的元素，因此这项研究适合于量子计算技术的更广泛的研究工作。相干QPS设备的开发将为开发具有潜在技术重要性的各种新设备以及基础研究开辟道路。相干QPS设备可能会在基础科学和计量学中找到应用，其影响可能与超导量子干涉设备（或SQUID）一样显著，这是我们将开发的相干QPS设备之一的双重。这些设备也可能与量子计算应用有关，既可以作为量子位本身，也可以作为使用先前开发的固态量子位的未来实现中的有用电路元件。基于量子点的量子电流标准也有可能被开发出来，这将对计量界产生重大影响。当超导序参量中的量子涨落足够强以至于序参量的相位发生滑移时，就会发生量子相位滑移。每个装置的关键元件将是超导纳米线。如果这样的纳米线具有足够小的横截面，则量子波动可能具有显著的影响并且可能发生QPS事件。在这种情况下，电荷和超导相之间的基本量子力学海森堡不确定性关系可能会显著改变流过设备的电流，甚至违反直觉地完全阻止电荷沿导线沿着传输，即使它是超导的。这是物理学的量子力学性质的结果。在这项研究中，我们将开发基于量子相位滑移的设备，使用伦敦纳米技术中心最先进的纳米纤维设备。我们将首次通过实验实现一系列相干QPS器件-包括磁通偏置和电流偏置QPS晶体管和QPS盒-以用于未来的器件应用，并且我们将建立和完善以前的实验工作，旨在实现基于原型的QPS电流标准。

We will develop superconducting devices to enable applications in high-technology electronics, based on a quantum-mechanical phenomenon known as quantum phase-slip (QPS). The proposal as a whole is concerned with developing this so-far-little-developed manifestation of quantum mechanics within superconducting nanowires. The developments will be both in our fundamental understanding of the physics, through experimental tests of recently proposed theories, and in moving towards concrete applications by development of circuit elements which will be useful in future nanoscale applications. One specific area of potential for future application is as elements for qubit technologies and thus the research fits into the broader research effort of enabling technologies for quantum computing.The development of coherent QPS devices would open up avenues for developing a gamut of new devices of potential technological importance, as well as for fundamental research. Coherent QPS devices are likely to find applications in both fundamental science and metrology, and the impact could be as marked as the superconducting quantum interference device (or SQUID), which is dual to one of the coherent QPS devices we will develop. The devices are also likely to be of relevance to quantum computing applications, both as qubits in the own right and also as useful circuit elements in future realisations using previously developed solid-state qubits. There is also potential for a QPS-based quantum current standard to be developed and this would have substantial impact on the metrology community.A quantum phase-slip occurs when quantum fluctuations in the superconducting order parameter are sufficiently strong that the phase of the order parameter slips. The key element of each device will be a superconducting nanowire. If such a nanowire has a cross-section sufficiently small, quantum fluctuations may have significant effects and QPS events may occur. In that case, the fundamental quantum-mechanical Heisenberg uncertainty relation between the charge and superconducting phase may noticeably change the current flow through the device and even, counterintuitively, completely block charge transport along the wire, even though it is superconducting. This is a result of the quantum-mechanical nature of the physics.In this research we will develop devices based on the quantum phase-slip, using the state-of-the-art nanofabrication facilities in the London Centre for Nanotechnology. We will experimentally realise a range of coherent QPS devices - including the flux-biased and current-biased QPS transistors and the QPS box - for the first time, with a view to future applications in devices, and we will build on and refine previous experimental work with the aim of realising a prototype QPS-based current standard.