Quantum devices: engineering electronic coherence in nanostructures

量子器件：纳米结构中的工程电子相干性

• 批准号: 312445-2011
• 负责人: Folk, Joshua
• 金额: $ 4.15万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571746
• 关键词: Quantum; devices; engineering; electronic; coherence

Our group builds and measures nanoscale electronic devices whose geometries are designed to yield new physics from a transport (resistance) measurement. Our experiments are performed at low temperature--typically less than 1 Kelvin--where electronic properties are dominated by coherent quantum mechanical effects. In this limit, signals sent from laboratory equipment to the device under test provide in situ control over quantum mechanical degrees of freedom. We propose a three-pronged approach to our research in the coming 5 years. The first builds off of our most successful set of experiments from the past 5 years; the second continues our group's expansion into one of the hottest new fields in condensed matter physics; the third takes advantage of our group's unique position to move into a new direction with great potential payoff: 1. We recently discovered a new phenomenon called ballistic spin resonance, in which spin-orbit interaction couples to geometric resonances to give fast spin rotations in a semiconductor (GaAs) device. Until now these spin rotations were detected only by a fast effective spin relaxation rate, but here we propose to exploit this this phenomenon for fast and tunable spin rotations as well. 2. Despite widespread predictions for long spin coherence times in single atomic layers of carbon known as graphene, very little is known from an experimental point of view about the behaviour of electron and hole spins in a practical sample. Our group made inroads into this area, demonstrating the first interference-based spin current measurement in graphene. We will greatly expand this area of research, applying our existing expertise in GaAs spin measurements to study spin coherence in graphene. 3. Groups around the world are only within the last year recognizing the influence that surface atoms can have on graphene's electronic properties. Here we propose to dramatically change graphene's properties in an intentional way by depositing particular atoms into and onto the graphene.

我们的小组构建和测量纳米级电子设备的几何形状旨在从运输（电阻）测量中产生新的物理。 我们的实验是在低温下进行的，在小于1 kelvin上 - 电子特性由连贯的量子机械效应主导。在此限制下，从实验室设备发送到测试设备的信号提供了对量子机械自由度的原位控制。在未来5年中，我们建议对我们的研究提出一种三管齐下的方法。第一个建立在过去5年来我们最成功的一套实验之上。第二个继续扩展到凝结物理学中最热门的新领域之一。第三个利用我们小组的独特立场，以巨大的潜在回报进入一个新的方向： 1。我们最近发现了一种称为弹道自旋共振的新现象，其中自旋轨道相互作用伴侣与几何共振，以在半导体（GAAS）设备中快速自旋旋转。到目前为止，仅通过快速有效的自旋松弛率检测到这些自旋旋转，但是在这里我们建议将这种现象利用快速，可调的自旋旋转。 2。尽管在称为石墨烯的单个原子层中对长期自旋相干时间进行了广泛的预测，但从实验性的角度来看，关于电子和孔旋转在实用样品中的行为，几乎没有知名度。我们的小组进入了这一领域，证明了石墨烯中首次基于干扰的自旋电流测量。 我们将大大扩展这一研究领域，应用我们在GAAS旋转测量中的现有专业知识来研究石墨烯中的旋转连贯性。 3.世界各地仅在去年内认识到表面原子对石墨烯电子特性的影响。 在这里，我们建议通过将特定原子沉积到石墨烯中，以故意的方式显着改变石墨烯的性质。