掺杂拓扑超导体超导序参量的研究

拓扑超导理论和实验研究是超导研究领域的新兴方向。由于拓扑超导边缘态存在的马约拉纳费米子满足非阿贝尔统计,可作为拓扑量子比特进行容错量子计算，拓扑超导体又被广泛认为是实现拓扑量子计算的基石。实现拓扑超导的主要方向之一是对拓扑绝缘体进行掺杂，而对其超导序参量的研究还存在诸多分歧，亟待发现更为本征的实验现象和开展系统性的研究。..本项目中，申请人将通过生长高质量的由掺杂诱导的超导单晶材料，并使用原位微加工技术制备出拓扑超导微纳单晶器件，克服传统块体样品的缺陷及测量不利因素，实现本征输运特性的准确表征；通过研究正常态和超导态下面内、面外各向异性上临界场和磁致电阻，揭示超导序参量的对称特性；探索调控超导性质的因素和超导配对机制。..申请人在前期拓扑超导材料领域的研究为本项目奠定了基础。本项目的顺利完成将为理解拓扑超导体的超导配对对称性类型和拓扑性质，以及设计拓扑超导器件提供实验依据。

The theoretical and experimental investigations of topological superconductors are novel directions in the research of superconductivity. Due to the existence of Majorana fermions in the edge state, which satisfy the non-Abelian statistics and can be used as topological quantum bits for fault-tolerant quantum computation, the topological superconductors are widely considered to be the cornerstone of topological quantum computation. Doping topological insulator is a primary direction towards the realization of topological superconductors. However, there is no consistent conclusion in the researches of superconducting order parameters of doped topological superconductors so far. To solve the experimental discrepancies, it is urgent to discovery more intrinsic phenomena and apply systematic efforts...In this project, the applicant will grow high-quality doped superconducting single crystal materials, use in-situ micro-fabrication technique to prepare micro- and nano-single crystal devices, overcome the defects in bulk sample and adverse factors as those in previous measurements, and eventually achieve accurate characterization of intrinsic transport characteristics. By studying the anisotropic in-plane upper critical field and magnetoresistance in the normal and superconducting state, the symmetry of the superconducting order parameter would be revealed. Furthermore, the factors controlling the superconducting properties and the superconducting pairing mechanism would also be explored...With sufficient preparation from applicant's previous work on topological superconducting materials, the successful implementing of this project will provide support for understanding the type of superconducting pairing symmetry and topological properties, as well as design of topological superconductor devices.