退磁效应诱导的二维涡旋拓扑磁振子能级退简并

Degeneration of 2-D twisted magnon modes induced by magnetic dipolar interaction

涡旋磁振子是一类携带有受到拓扑保护的内禀轨道角动量的自旋波。磁性量子理论给出了二维圆形铁磁纳米量子点中涡旋磁振子的解析刻画,并定义了其轨道角动量。在低维铁磁系统中,退磁效应(偶极-偶极相互作用)的存在诱导涡旋磁振子产生能级退简并(能级劈裂),使得具有不同拓扑荷的本征模式形成二能级系统。在外加驱动的激发下,涡旋磁振子二能级系统会出现能级跃迁。这使得构建超高速低功耗拓扑量子NOT门成为可能。以上结果得到了微磁学模拟的确认。

Twisted magnons are spinwave quantas carrying intrinsic angular momentum protected by their topological properties.Quantum mechanical theory of magnetisim leads to analytical desctriptions and solutions for twisted magnons in 2-dimensional disk-shaped ferromagnetic quantum dots,which relates the intrinsic angular moment to their topological charges.In such systems,magnetic dipolar interaction induces a splitting in energy levels of twisted magnons with opposite topological charges,defining a quasi-particle two level system.State transitions appear when the system undergos exciting from applied dynamical forces,which paves a new way to a topological NOT gate with extreme rapid switch clock.All the results are confirmed with full-fledged Micro-magnetism simulations.