基于离子栅调控的单层伊辛超导体物性及拓扑性质研究

非常规超导的序参量拥有非平庸相位，其中非中心对称超导的混合配对、拓扑超导的马约拉纳费米子，在超导机理研究和超导量子器件领域占有举足轻重的地位，位于凝聚态领域最前沿。离子栅诱导的单层伊辛型超导体，以范德华层状晶体-过渡金属硫族化物为载体，拥有空间反演对称性破缺和谷极化费米面，享有独立调节超导温度和自旋轨道耦合强度的优势，为系统性地探索非常规超导态的混合配对及其拓扑性质提供新的契机。目前，理论预测的自旋三重态、手征拓扑超导态等奇异物性还不明确，基本实验表征如超导能隙等尚无确切结论。本项目拟以离子栅和材料工程为调控手段，制备三种不同自旋轨道耦合强度的伊辛型超导体系；以人工堆叠范德华超导隧道结为实验对象，逐步深入获得超导能隙与外场调控参量的依赖关系、同位旋三重态的存在证据、单能带伊辛超导体及其拓扑性质，从而为揭示伊辛超导态的奇异配对提供参考，为二维拓扑超导性提供新的思路。

Non-conventional superconductivity is defined by an order parameter of non-trivial phase, where the mixture of spin singlet and triplet pairing in noncentrosymmetric superconductors and Majorana fermions generated in topological superconductors, play an important role in the investigation of pairing mechanism and next-generation superconducting quantum devices, thus attracting tremendous attention in the community of condensed matter physics. Ionic liquid gated monolayer Ising superconductor, based on van der Waals layered crystals-transition metal dichalcogenides (TMD), endows both inversion symmetry breaking and spin-valley locking, and has an advantage of independent control of superconducting critical temperature and spin-orbit coupling, providing new opportunities to systematic investigation of mixed pairing and non-trivial topology in non-conventional superconductors. Nevertheless, many theoretically proposed exotic properties such as spin triplet pairing, chiral topological superconductivity have not been confirmed, and the intrinsic properties of Ising superconductivity like superconducting order parameter and pairing mechanism have been far less explored experimentally. In this project, by using ionic gating and material engineering, we will prepare three kinds of Ising superconductors with distinct spin orbit coupling strength. By measuring tunneling spectra of van der Waals stacked superconducting heterostructures, we expect to obtain the relationship between superconducting gap and external physical parameters, evidences of iso-spin triplet, and the realization of single-band Ising superconductors and its topological properties, providing experimental support to clarify the exotic pairing mechanism and shedding light on two dimensional intrinsic topological superconductivity.