Transport Properties of Boron-Doped Nanocrystalline Diamond (BNCD)

本文主要研究了掺硼纳米金刚石(BNCD)超导薄膜的性能。BNCD系统是一个高度可调的系统，其中的电子载流子浓度可以通过掺硼水平来控制，允许从绝缘行为向超导行为的转变。这种材料是颗粒状的，颗粒的大小取决于薄膜的厚度和沉积过程的细节。我们目前正在发展接近超导转变温度(涨落电导率)的电导率增加的理论。在实验上，这显示了三个不同的区域，具有不同的幂定律行为，这被认为是由于库珀对相对于典型颗粒的大小。我们目前已经计算了对涨落电导率的所有贡献，并试图将它们与我们在CarDiffe的合作者的实验数据相一致。详细的拟合有望为提取BNCD和其他颗粒超导系统的各种材料参数提供一种方法。

The research is focussed on the properties of superconducting boron-doped nanocrystalline diamond (BNCD) films.The BNCD system is a highly tuneable system, where the electron carrier concentration can be controlled by the levelof boron doping, allowing a transition from insulating to superconducting behaviour. The material is granular, with thesize of the grains depending on the film thickness and details of the deposition process. We are currently developing thetheory for the increase in electrical conductivity close to the superconducting transition temperature (the fluctuation conductivity). Experimentally this shows three distinct regions with different power law behaviours, which is believed to be due to the size of the Cooper pair relative to that of a typical grain. We have currently calculated all the contributions to the fluctuation conductivity, and are trying to reconcile them with the experimental data from our collaborators in Cardiff.Detailed fitting will hopefully provide a method for extracting various material parameters of BNCD and other granularsuperconducting systems.