He3-Cryostat with superconducting magnet

我们申请资助一个he3冷却低温恒温器与超导磁体集成的自制扫描隧道显微镜。为了达到下面指定的科学目标，我们的目标是样品温度< 500 mK。扫描隧道显微镜的可靠运行需要低机械噪声。在现有的超高真空系统中集成需要cf兼容的法兰。低温恒温器将用于实现以下科学目标：(i)研究潜在的拓扑超导体和（ii）表征纯和（磁）掺杂拓扑绝缘体的电子状态。新系统将使我们能够更好地了解上述材料系统。我们将设计并组装一种低温扫描隧道显微镜，其基本样品温度在350 mK至500 mK之间，从而与我们研究小组已经使用的显微镜相比，将能量分辨率提高约2.5 - 3倍。在(i)的背景下，所要求的设置将使我们能够访问样品系统，由于其临界温度非常低，目前无法研究其超导特性。此外，更好的能源分辨率将允许更好地区分潜在的马约拉纳州和其他竞争效应，如柴巴州和卡洛里-德热内斯-马里肯州。关于（ii）增强的能量分辨率将允许更好地理解拓扑绝缘体中的朗道能级寿命，我们希望解开相关的散射特性。

We request funding for a He3-cooled cryostat with a superconducting magnet for the integration of a home-built scanning tunneling microscope. In order to meet the scientific goals specified below we aim for a sample temperature < 500 mK. Low mechanical noise is required for reliable operation of the scanning tunneling microscope. The integration in an already existing ultra-high vacuum system requires CF-compatible flanges. The cryostat will be used for reaching the following scientific goals: (i) The investigation of potential topological superconductors and (ii) the characterization of electronic states of pure and (magnetically) doped topological insulators. The new system will enable us to achieve better insight into the above-mentioned material systems. We will design and assemble a low-temperature scanning tunneling microscope with a base sample temperature between 350 mK bis 500 mK, thereby enhancing the energy resolution by about a factor of 2,5–3 in comparison to microscopes already in use in our research group. In the context of (i) the requested setup will be enable us to access sample systems the superconducting properties of which could not be investigated so far because of their very low critical temperature. Furthermore, the much better energy resolution will allow for a better separation between potential Majorana states and other, competing effects, such as Shiba and Caroli-de Gennes-Matricon states. Regarding (ii) the enhanced energy resolution will allow for a better understanding of the Landau level life time in topological insulators where we hope to unravel the relevant scattering properties.