The development of a new nuclear magnetic resonance method using ballistic conductance and the detection of a small amount of molecules

我们在单层石墨薄膜上尝试核磁共振。在早期阶段，我们检测到由于氧吸附在薄膜表面而引起的电导变化。我们研究了电导变化与温度的关系。但由于薄膜表面不够干净，我们的系统检测灵敏度较低。我们对微加工工艺进行了改进，并尝试了几种退火方法（氢气和氩气混合退火、电流退火等）来制备干净的表面，但没有取得明显的改善。我们继续这项研究，并使用扫描探针显微镜和扫描近场光学显微镜测量表面污染的信息。

We try NMR on a monolayer of graphite film. As an early stage, we detected a change in conductance caused by oxygen adsorption onto the film surface. We investigated the temperature dependence of the change in conductance. But the detection sensitivity of our system turned out to be low since the film surface was not clean enough. We modified the micro fabrication process and tried several annealing methods (annealing in the mixture of hydrogen and argon, current annealing etc.) for preparing clean surface but remarkable improvement was not obtained. We continue this research and make measurements with a scanning probe microscope and a scanning near field optical microscope for the information on surface contamination.