标题： 磁性隧道结的重构作为将其转变为无场涡旋振荡器的方法 显示英文标题

标题： Reconfiguration of a Magnetic Tunnel Junction as a Way to Turn It into a Field-Free Vortex Oscillator

摘要： 磁性隧道结（MTJs）是实用自旋电子学中的关键元件，不仅能够实现传统的任务，如数据存储、传输和处理，还能够实现内存计算处理元件，促进类脑计算高效硬件的发展。 MTJ的功能由其自由层（FL）和具有固定磁化的参考层（RL）的特性决定，这两个层由MgO隧道势垒隔开。 本文提出了一种重新配置RL的机制，RL是钉扎合成反铁磁体的上层，能够实现从单域状态到不同核心位置的涡旋磁态的可逆转变。 当RL处于涡旋状态时，它会产生具有类似涡旋极化分布的自旋电流，即使在没有外部磁场的情况下，也能在FL中实现稳定的涡旋振荡。 这种效应已在直径范围为400至1000纳米的MTJs中得到证实。 使用实验数据和比较微磁模拟表明，钉扎反铁磁体保留了先前再退火状态的长期记忆，导致涡旋极化自旋电流发生形变，进而引入强动态涡旋核心极性对称性破坏。 MTJ静态和动态特性的模拟可编程性质展示了将非易失性引入射频自旋电子类脑范式的不同可能途径。 显示英文摘要

摘要： Magnetic tunnel junctions (MTJs) are key elements in practical spintronics, enabling not only conventional tasks such as data storage, transmission, and processing but also the implementation of compute-in-memory processing elements, facilitating the development of efficient hardware for neuromorphic computing. The functionality of an MTJ is determined by the properties of its free layer (FL) and reference layer (RL) with fixed magnetization, separated by an MgO tunnel barrier. This paper presents a mechanism for reconfiguring the RL, which is the upper layer of a pinned synthetic antiferromagnet, enabling a reversible transition from a single-domain state to a vortex magnetic state with different core positions. When the RL is in the vortex state, it generates a spin current with a vortex-like polarization distribution, enabling stable vortex oscillations in the FL even in the absence of external magnetic fields. This effect has been confirmed in MTJs with diameters ranging from 400 to 1000 nm. It is demonstrated, using experimental data with comparative micromagnetic simulation, that the pinning antiferromagnet retains a long term memory of previous reannealing states resulting in a deformation of the vortex polarised spin current, which in turn introduces a strong dynamical vortex core polarity symmetry breaking. The analogue reprogrammable nature of both the static and dynamic properties of the MTJ demonstrate different possible routes for the introduction of non-volatility into radiofrequency spintronic neuromorphic paradigms.