Probing topologically enhanced interface magnetism

Topologically nontrivial materials are a material class which has emerged over the past decade+ as a critical area of research due to promise for ultra-low power computing or fault-tolerant quantum devices. As the classes of accessible topological materials have expanded, transitions between topological states may enable a wide range of new devices. In particular, the Dirac semimetal ZrTe5 is near a transition to both weak and strong topological insulating states, which may enable tuning in and out of macroscopic quantum transport conditions. Here, we propose to study the introduction of magnetic order in to ZrTe5 by the magnetic insulator EuS, as the time-reversal symmetry breaking induced by magnetic order at the surface is crucial to realizing the quantum anomalous Hall state in this material.

拓扑非平凡材料（Topologically nontrivial materials）是近十余年来兴起的一类重要研究材料体系，因其在超低功耗计算或容错量子器件领域展现出巨大应用潜力而成为核心研究方向。随着可获取的拓扑材料种类持续拓展，不同拓扑态间的相变有望催生诸多新型器件。具体而言，狄拉克半金属（Dirac semimetal）ZrTe5 正处于向弱拓扑绝缘态与强拓扑绝缘态转变的临界区域，该特性可实现宏观量子输运状态的可逆调控。鉴于材料表面磁有序诱导的时间反演对称性（time-reversal symmetry）破缺是在该体系中实现量子反常霍尔态（quantum anomalous Hall state）的关键前提，本研究拟通过磁性绝缘体（magnetic insulator）EuS 在 ZrTe5 中引入磁有序并开展相关研究。