Title: Full-scale field-free spin-orbit switching of the CoPt layer grown on vicinal substrates Show Chinese title

Title: 全尺寸无场自旋轨道切换在倾斜衬底上生长的CoPt层

Abstract: A simple, reliable and field-free spin orbit torque (SOT)-induced magnetization switching is a key ingredient for the development of the electrical controllable spintronic devices. Recently, the SOT induced deterministic switching of the CoPt single layer has attracts a lot of interests, as it could simplifies the structure and add new flexibility in the design of SOT devices, compared with the Ferromagnet/Heavy metal bilayer counterparts. Unfortunately, under the field-free switching strategies used nowadays, the switching of the CoPt layer is often partial, which sets a major obstacle for the practical applications. In this study, by growing the CoPt on vicinal substrates, we could achieve the full-scale (100% switching ratio) field-free switching of the CoPt layer. We demonstrate that when grown on vicinal substrates, the magnetic easy axis of the CoPt could be tilted from the normal direction of the film plane; the strength of Dzyaloshinskii Moriya interaction (DMI) would be also be tuned as well. Micromagnetic simulation further reveal that the field-free switching stems from tilted magnetic anisotropy induced by the vicinal substrate, while the enhancement of DMI help reducing the critical switching current. In addition, we also found that the vicinal substrates could also enhance the SOT efficiency. With such simple structure, full-scale switching, tunable DMI and SOT efficiency, our results provide a new knob for the design SOT-MRAM and future spintronic devices. Show Chinese abstract

Abstract: 一种简单、可靠且无需外加磁场的自旋轨道矩（SOT）诱导的磁化翻转是开发电控自旋电子器件的关键要素。 最近，CoPt单层的SOT诱导确定性翻转引起了广泛关注，因为它相比铁磁体/重金属双层结构，可以简化结构并在SOT器件设计中增加新的灵活性。 不幸的是，目前使用的无磁场翻转策略下，CoPt层的翻转通常是部分的，这给实际应用带来了重大障碍。 在本研究中，通过在倾斜衬底上生长CoPt，我们可以实现CoPt层的全尺度（100%翻转率）无磁场翻转。 我们证明，当在倾斜衬底上生长时，CoPt的磁易轴可以从薄膜平面的法线方向倾斜；Dzyaloshinskii Moriya相互作用（DMI）的强度也可以被调节。 微磁模拟进一步表明，无磁场翻转是由于倾斜衬底引起的倾斜磁各向异性，而DMI的增强有助于降低临界翻转电流。 此外，我们还发现倾斜衬底也可以提高SOT效率。 凭借这种简单的结构、全尺度翻转、可调的DMI和SOT效率，我们的结果为SOT-MRAM和未来自旋电子器件的设计提供了一个新的调控手段。