论文标题
使用扫描钻石磁力计的双层石墨烯中$ $ $ $ $ $ $ $ $ $的成像
Imaging of sub-$μ$A currents in bilayer graphene using a scanning diamond magnetometer
论文作者
论文摘要
纳米级电子传输产生了许多有趣的物理现象，这些现象伴随着当前流动的不同空间模式。在这里，我们在室温下报告了双层石墨烯中二维电流分布的敏感磁成像。通过将源水流电流的动力调制与钻石探针中氮相位中心的AC量子感测的动态调制相结合，我们分别获得磁场和电流密度图，其优异灵敏度分别为4.6 NT和20 Na/$ $ m $ M。空间分辨率为50-100 nm。我们进一步引入了一组方法，以增加技术的动态范围，并减轻电子传输上磁力测定操作的不想要的反作用。电流密度图揭示了通过后门电势对流动流的流动模式和全局调整的局部变化。未观察到流体动力转运的特征。我们的实验证明了在二维材料和导体中成像纳米级传输的微妙特征的可行性。
Nanoscale electronic transport gives rise to a number of intriguing physical phenomena that are accompanied by distinct spatial patterns of current flow. Here, we report on sensitive magnetic imaging of two-dimensional current distributions in bilayer graphene at room temperature. By combining dynamical modulation of the source-drain current with ac quantum sensing of a nitrogen-vacancy center in a diamond probe, we acquire magnetic field and current density maps with excellent sensitivities of 4.6 nT and 20 nA/$μ$m, respectively. The spatial resolution is 50-100 nm. We further introduce a set of methods for increasing the technique's dynamic range and for mitigating undesired back-action of magnetometry operation on the electronic transport. Current density maps reveal local variations in the flow pattern and global tuning of current flow via the back-gate potential. No signatures of hydrodynamic transport are observed. Our experiments demonstrate the feasibility for imaging subtle features of nanoscale transport in two-dimensional materials and conductors.
