Investigating deep defects in 28Si for potential applications in quantum information and communication

我们的现代技术是基于量子力学的能力，以完美地描述（如果只是概率）纳米系统的行为。人们越来越认识到，量子力学的原理可以更直接地用于新的“量子技术”，这在通信、安全和计算方面具有全新的和潜在的破坏性应用的巨大潜力。在量子计算机（QC）中，叠加允许传统计算机位的0和1被无限范围的0和1的叠加所取代，从而产生量子位或量子位。量子比特可以通过纠缠连接起来，这样一个量子比特的测量就会影响另一个量子比特的测量结果，即使它们是分开的。这违背了我们的直觉，因为它是基于宏观实在的，但可以完全由量子力学解释。我们现在知道，对于某些重要的问题，QC可能比最大的传统计算机更强大，更快。这种范式转变的潜力正在推动世界各地的激烈研究，以找到一种技术，使QC的足够复杂，以解决这一广泛的问题。从光子到原子，再到电子和核自旋等亚原子粒子，各种各样的系统正在被研究。许多活动都集中在硅（Si）为基础的方法，因为硅是我们目前的计算和信息技术的基础。如果能够开发出合适的量子比特以及制备、耦合和测量它们的方法，现有的硅材料科学和纳米器件技术可以用来建立QC。我们发现富集的28 Si具有独特的性质：28 Si中的光学跃迁线宽比正常Si（或任何其他半导体）中的要尖锐得多，这导致了控制和测量杂质的电子和核自旋的新方法，这些杂质是Si中量子比特的主要候选者。这些技术展示了创纪录的相干寿命-量子位可以保持的时间-引起了全球的关注，包括物理学世界年度十大突破（2013）。使用这些相同的技术，我们最近发现了制造与Si光子兼容的高度可再现单光子源的全新可能性，这解决了那些试图构建基于光子的量子技术的人的突出需求。这些令人兴奋的单光子源还提供了一种将芯片上的多个量子位与单个光粒子连接起来的方法，为大规模硅基QC铺平了道路。这笔赠款将使我们能够建立在我们的成就和合作，并继续在这一领域设定新的方向。 具体来说，我们将培养未来的领导者，配备在半导体，光学，低温和量子信息理论的专业知识，谁将有助于使量子技术的承诺成为现实。

Our modern technology is based on the ability of quantum mechanics to describe perfectly (if only probabilistically) the behavior of nanoscale systems. There is a growing appreciation that the principles of quantum mechanics can be used more directly in new `quantum technologies', which have spectacular potential for completely new and potentially disruptive applications in communications, security, and computing. In a quantum computer (QC), superposition allows the 0 and 1 of a conventional computer bit to be replaced by an infinite range of superpositions of 0 and 1, giving a quantum bit, or qubit. Qubits can be linked using entanglement so that a measurement on one affects the outcome of a measurement on the other, even when separated. This defies our intuition, based as it is on macroscopic reality, but can be completely accounted for by quantum mechanics. We now know that for certain classes of important problems, a QC could be enormously more powerful and faster than the largest imaginable conventional computer. This paradigm-shifting potential is fueling intense research around the world to find a technology for making a QC of sufficient complexity to solve this broad class of problems. A wide range of systems is being investigated, from photons to atoms to subatomic particles such as electrons and nuclear spins. Much activity is focused on silicon (Si)-based approaches, since Si is the basis for our present computing and information technologies. The existing Si materials science and nanoscale device technology could be harnessed to build a QC, if suitable qubits and the means of preparing, coupling and measuring them can be developed. Our discovery that enriched 28Si has a unique property: the linewidths of optical transitions are much sharper in 28Si than in normal Si (or in any other semiconductor), led to new methods for controlling and measuring the electron and nuclear spins of impurities, which are prime candidates for qubits in Si. These techniques demonstrated record-setting coherence lifetimes - the time for which a qubit can be maintained - which attracted significant global attention, including a Physics World Top Ten Breakthrough of the Year (2013). Using these same techniques, we recently identified entirely new possibilities for making highly reproducible single photon sources compatible with Si photonics, which addresses an outstanding need for those trying to build photon-based quantum technologies. These exciting single photon sources also offer a way to link multiple qubits on-chip with individual particles of light, paving the way towards a large-scale silicon-based QC. This grant will allow us to build on our achievements and collaborations, and to continue to set new directions in this field.  Specifically, we will train future leaders, equipped with expertise in semiconductors, optics, cryogenics and quantum information theory, who will contribute to making the promise of quantum technologies a reality.