Microwave spectroscopy and materials

这项名为“材料和微波”的提案将支持一个跨学科项目，研究复杂电子材料的生长及其物理性质的测量。通过探索相关的过渡金属氧化物以及通过化学掺杂、氧有序和高压改变其性质的方法，材料计划建立在我们在世界上最清洁的高温超导体YBCO晶体生长方面的现有实力之上。这将包括在高温超导体家族的另一个杰出成员Tl2201中实现高水平的完美晶体的重大努力。随着这些材料掺杂的改变，超导性的演变将通过一套内部测量材料的电子特性来测量，包括各种测量微波功率吸收的技术，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使用新的宽带微波光谱设备研究其他奇异的电子材料。这项新的实验技术将使我们能够测量微波频率范围内冷却到绝对零度以下1度的样品的功率吸收。在这样的低温下，有许多物理现象和物质的奇异状态，在新光谱仪的微波范围内，在相应的低频率上，预计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.