Optical study of quantum materials

量子材料的光学研究

• 批准号: 2534-2013
• 负责人: Timusk, Thomas
• 金额: $ 4.37万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633121
• 关键词: Optical; study; quantum; materials

This proposal is for basic research on quantum materials with properties that cannot be explained with our current knowledge of physics and chemistry. If we understand how these materials work, we will be in a better position to take advantage of their strange and wonderful properties. Four projects are proposed. They all involve the uses infrared radiation as a probe.The first arises from our recent discovery of the breakdown of the widely accepted model for the frequency dependence of the electrical resistance in metals at low temperatures, the Landau Fermi liquid theory. We find that the theory fails in all cases where this dependence has been measured and want to test this further. Our work has been accepted by the high impact journal PNAS. The second project is a search for a new state of matter, the Dirac-Weyl semimetal. So far, no examples of this has been found but we have located a promising suspect: quasicrystals. They seem to have the properties needed: they are neither metals nor insulators but have strange in-between properties, an energy gap exactly at zero frequency, a property that results from topology. The third project involves our continued study of high temperature superconductivity using infrared, in novel materials. We will use our high magnetic field facility to look for the spin density wave state predicted to exist at high fields. The fourth project that ties the others together is an improvement of infrared techniques to keeps us on the forefront in the field. We will attempt to use infrared spectroscopy in pulsed ultra high magnetic fields. As an example of our past performance in this area, Sciencetech in London Ontario, founded by graduates from my group in part, manufactures an infrared spectrometer, the SPS-300, shipped to customers world wide. We designed it and my students wrote its original operating software. ESA used it to calibrate the Planck satellite that was launched to measure the microwave background radiation from the big bang.

该提案适用于量子材料的基础研究，其性质无法用我们现有的物理和化学知识来解释。如果我们了解这些材料的工作原理，我们将能够更好地利用它们奇怪而奇妙的特性。提出了四个项目。它们都涉及使用红外辐射作为探针。第一个原因是我们最近发现了广泛接受的低温金属电阻频率依赖性模型（朗道费米液体理论）的崩溃。我们发现该理论在所有测量了这种依赖性的情况下都失败了，并且希望进一步测试这一点。我们的工作已被高影响力期刊 PNAS 接受。第二个项目是寻找一种新的物质状态，即狄拉克-韦尔半金属。到目前为止，还没有发现这样的例子，但我们找到了一个有希望的嫌疑人：准晶体。它们似乎具有所需的特性：它们既不是金属也不是绝缘体，但具有奇怪的中间特性，即恰好处于零频率的能隙，这是拓扑产生的特性。第三个项目涉及我们在新型材料中利用红外线继续研究高温超导性。我们将使用我们的高磁场设施来寻找预计存在于高磁场中的自旋密度波态。将其他项目联系在一起的第四个项目是红外技术的改进，使我们保持在该领域的前沿。我们将尝试在脉冲超高磁场中使用红外光谱。作为我们过去在这一领域表现的一个例子，位于安大略省伦敦的 Sciencetech 公司由我所在团队的部分毕业生创立，生产红外光谱仪 SPS-300，并销往世界各地的客户。我们设计了它，我的学生编写了它的原始操作软件。欧空局用它来校准发射的普朗克卫星，以测量大爆炸产生的微波背景辐射。