Spintronics with graphene-hexagonal boron nitride van der Waals heterostructures
Spintronics with graphene-hexagonal boron nitride van der Waals heterostructures
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DOI：
10.1063/1.4902814
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发表时间：
2014-11
影响因子：
4
通讯作者：
M. Kamalakar;André Dankert;J. Bergsten;T. Ive;S. Dash
中科院分区：
文献类型：
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作者：
M. Kamalakar;André Dankert;J. Bergsten;T. Ive;S. Dash
六方氮化硼（h - BN）是一种具有大带隙的类石墨烯绝缘同素异形体，非常适合用于原子级薄的隧道势垒应用。在本文中，我们展示了大面积化学气相沉积（CVD）的h - BN作为石墨烯自旋输运器件中一种有前景的自旋隧道势垒。在这类结构中，发现具有h - BN势垒的铁磁隧道接触在大尺度上展现出稳健的隧道特性，其电阻处于有利于高效自旋注入石墨烯的合适范围。非局域自旋输运和进动实验表明，在100 K时，石墨烯中的自旋寿命约为500 ps，自旋扩散长度约为1.6 μm，隧道自旋极化率约为11%。在不同注入偏置电流和栅极电压下进行的电学和自旋输运测量证实了通过h - BN势垒的隧道自旋注入。这些结果为在自旋电子技术中应用大面积CVD h - BN开辟了可能性。
Hexagonal boron nitride (h-BN) is a large bandgap insulating isomorph of graphene, ideal for atomically thin tunnel barrier applications. In this letter, we demonstrate large area chemical vapor deposited (CVD) h-BN as a promising spin tunnel barrier in graphene spin transport devices. In such structures, the ferromagnetic tunnel contacts with h-BN barrier are found to show robust tunneling characteristics over a large scale with resistances in the favorable range for efficient spin injection into graphene. The non-local spin transport and precession experiments reveal spin lifetime ≈500 ps and spin diffusion length ≈1.6 μm in graphene with tunnel spin polarization ≈11% at 100 K. The electrical and spin transport measurements at different injection bias current and gate voltages confirm tunnel spin injection through h-BN barrier. These results open up possibilities for implementation of large area CVD h-BN in spintronic technologies.