CIC nanoGUNE BRTA, 20018 Donostia-San Sebastian, Basque Country, Spain.
Departamento de Polímeros y Materiales Avanzados: Física Química y Tecnología Facultad de Químicas, UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain.
Nano Lett. 2023 May 24;23(10):4406-4414. doi: 10.1021/acs.nanolett.3c00687. Epub 2023 May 4.
Graphene is a light material for long-distance spin transport due to its low spin-orbit coupling, which at the same time is the main drawback for exhibiting a sizable spin Hall effect. Decoration by light atoms has been predicted to enhance the spin Hall angle in graphene while retaining a long spin diffusion length. Here, we combine a light metal oxide (oxidized Cu) with graphene to induce the spin Hall effect. Its efficiency, given by the product of the spin Hall angle and the spin diffusion length, can be tuned with the Fermi level position, exhibiting a maximum (1.8 ± 0.6 nm at 100 K) around the charge neutrality point. This all-light-element heterostructure shows a larger efficiency than conventional spin Hall materials. The gate-tunable spin Hall effect is observed up to room temperature. Our experimental demonstration provides an efficient spin-to-charge conversion system free from heavy metals and compatible with large-scale fabrication.
石墨烯由于其低自旋轨道耦合，是一种用于长距离自旋输运的轻材料，这同时也是表现出可观的自旋霍尔效应的主要障碍。据预测，轻原子的修饰可以在保持长自旋扩散长度的同时提高石墨烯中的自旋霍尔角。在这里，我们将轻金属氧化物（氧化铜）与石墨烯结合，以诱导自旋霍尔效应。其效率由自旋霍尔角和自旋扩散长度的乘积给出，可通过费米能级位置进行调节，在电荷中性点附近达到最大值（100 K 时为 1.8 ± 0.6 nm）。这种全轻元素异质结构比传统的自旋霍尔材料具有更高的效率。观察到的栅极可调自旋霍尔效应可高达室温。我们的实验演示提供了一种高效的自旋到电荷转换系统，它不含重金属，并且与大规模制造兼容。
