一维超导纳米线准Majorana零能模的可控调制及其量子比特的理论研究

马约拉纳零能模在实现拓扑量子计算上有巨大的应用前景，可演生于一维超导纳米线的拓扑超导态。然而，至今仍然没有实验可以确切证实马约拉纳零能模的存在。拓扑平庸的准马约拉纳零能模具有与马约拉纳零能模极其相似的特性，是目前探测、证实马约拉纳零能模最大的困扰之一。值得关注的是，在真实纳米线体系中，准马约拉纳零能模可普遍存在且易于获得，甚至能在基于测量的编织方案下完成有效的拓扑编织。因而充分有效地利用准马约拉纳零能模具有非常重大的物理意义。目前对准马约拉纳零能模的演化及拓扑保护机制的理解还不清楚，而基于其构筑有效拓扑量子比特的相关研究也亟需探索和挖掘。本项目拟基于一维超导纳米线体系，模拟、设计准马约拉纳零能模可调控的结构模型，进而以之构筑基于测量编织的有效量子比特，并探究其比特的基本特性。可以预期，本项目的开展将有望开辟一条短期内基于准马约拉纳零能模实现拓扑量子计算的更切实可行的新路径。

Majorana zero modes, which can emerge in the topological superconducting state of the 1D superconducting nanowire, have a significantly huge potential in realizing topological quantum computation. However, there is no sufficient unambiguous proof of the existence of Majorana zero modes in experiments so far. Despite being a topologically trivial state, quasi-Majorana zero modes behave surprisingly similar to the topologically protected Majorana zero modes and have developed into one of the most formidable obstacles in realizing and detecting the Majorana zero modes at the current stage. It is noteworthy, however, quasi-Majorana zero modes tend to be more generic as well as easier to be reached in practice in the realistic superconducting nanowires, and even can support the effective braiding in the scheme of measurement-based braiding. Therefore, effectively making use of the quasi-Majorana zero modes is of extremely scientific importance in this research area. However, it is still unclear regarding how the quasi-Majorana zero modes evolve and are topologically protected in the nanowires. In addition, building the functional quasi-Majorana zero modes-based topological qubits indeed deserves significant and immediate attention, which unfortunately has not yet been studied so far. This project will design and model theoretically the effective structure of 1D superconducting nanowire where the quasi-Majorana zero modes are finally controllable. Based on that, this project will then focus on the scheme of the measurement-based braiding, build the functional topological qubits, study their properties relevant to braiding along with the experimentally reachable reading and gating operations. It is expected that this study will ultimately provide a more practical approach to realizing topological quantum computation.