Microwave spectroscopy and materials

题为“材料和微波”的提案将支持复杂电子材料生长及其物理特性测量的跨学科研究计划。该材料计划建立在我们现有的优势，通过探索相关的过渡金属氧化物和通过化学掺杂，氧有序和高压改变其性质的方法，生长世界上最干净的高温超导体YBCO晶体。这将包括在Tl2201中实现高水平的晶体完美性的重大努力，Tl2201是高温超导体家族的另一个突出成员。随着这些材料的掺杂改变，超导性的演变将通过一套材料电子特性的内部测量来测量，包括测量微波功率吸收的各种技术，超流体的密度，以及首次在高温超导体中测量伦敦霍尔效应的新设备。这些将与我们在加拿大和国外的合作者提供的大量其他实验技术结合在一起。反过来，合作网络将使我们能够获得其他奇异的电子材料，这些材料将通过新的宽带微波光谱设备进行研究。这种新的实验技术将使我们能够测量在绝对零度以上1度以下冷却的样品在微波频率范围内的功率吸收。在这些低温下，有许多物理现象和奇异的物质状态，预计在新光谱仪的微波范围内，在相应的低频下会有不寻常的电子吸收。

The proposal entitled 'Materials and Microwaves' will support an interdisciplinary program of research on the growth of complex electronic materials and measurement of their physical properties. The materials program builds on our existing strength in the growth of the world's cleanest crystals of the high temperature superconductor YBCO by exploring related transition metal oxides and the means of altering their properties through chemical doping, oxygen ordering and high pressure. This will include a major effort to achieve a high level of crystalline perfection in Tl2201, another prominent member of the family of high temperature superconductors. The evolution of superconductivity as the doping of these materials is altered will be measured with a suite of in-house measurements of the electronic properties of the materials, including a variety of techniques for measuring microwave power absorption, the density of the superfluid, and a new apparatus to measure, for the first time in a high temperature superconductor, the London Hall effect. These will be brought together with a large array of other experimental techniques available through our collaborators in Canada and abroad. In turn the network of collaborations will give us access to other exotic electronic materials which will be studied with a new broadband microwave spectroscopy facility. This new experimental technique will allow us to measure power absorption in the microwave frequency range in samples cooled below 1 degree above absolute zero. At these low temperatures there are numerous physical phenomena and exotic states of matter that are expected to have unusual electronic absorption at correspondingly low frequencies, in the microwave range of the new spectrometer.