Neutral-current Hall effects in disordered graphene
Neutral-current Hall effects in disordered graphene
复制标题
无序石墨烯中的中性电流霍尔效应
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
M. Fuhrer
中科院分区：
文献类型：
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作者：
Yilin Wang;Xinghan Cai;J. Reutt;M. Fuhrer
非局域霍尔棒几何结构被用来检测石墨烯对二氧化硅的中性电流霍尔效应。无序是通过在超高真空中添加Au或Ir吸附原子来调节的。在制备的石墨烯和吸附原子修饰的石墨烯中都发现了可重复的中性电流霍尔效应。霍尔角对栅极电压和无序度表现出复杂但可重复的依赖关系，并显著破坏了电子-空穴对称性。霍尔和反霍尔探针之间的长度指数关系表明，中性电流弛豫长度约为300 nm。平行磁场中的短弛豫长度和无进动表明，中性电流为谷流。在7-300K温度范围内几乎没有温度依赖性，这是前所未有的，并有望用于室温中性电流电子学的受控无序。
A non-local Hall bar geometry is used to detect neutral-current Hall effects in graphene on silicon dioxide. Disorder is tuned by the addition of Au or Ir adatoms in ultra-high vacuum. A reproducible neutral-current Hall effect is found in both as-fabricated and adatom-decorated graphene. The Hall angle exhibits a complex but reproducible dependence on gate voltage and disorder, and notably breaks electron-hole symmetry. An exponential dependence on length between Hall and inverse-Hall probes indicates a neutral current relaxation length of approximately 300 nm. The short relaxation length and lack of precession in parallel magnetic field suggest that the neutral currents are valley currents. The near lack of temperature dependence from 7-300 K is unprecedented and promising for using controlled disorder for room temperature neutral-current electronics.