We studied the adsorption of atomic hydrogen on monolayer graphene and quasi free monolayer graphene, epitaxially grown on SiC(0001). By means of in-situ surface transport measurements, a metal-insulator transition was found on both n- and p-type doped two dimensional electron systems. The detailed analysis of the temperature dependent resistivity revealed that even ultra-low concentrations ($n_H\approx {10}^{12}$ cm${}^{-2}$) of locally chemisorbed H-clusters act as effective scattering centers for the propagating electrons and limit the mean-free path $L_0\propto 1/\sqrt{n_H}$. Despite the weak disorder due to adsorption, strong localization was found. The activation energy for destroying the phase coherence within the system is around 30 meV. Our analysis rules out the formation of a band insulator or even a”bad metal” due to adsorption of hydrogen.

我们研究了外延生长在SiC（0001）上的单层石墨烯和准自由单层石墨烯上原子氢的吸附。通过原位表面传输测量，在n型和p型掺杂的二维电子系统上都发现了金属-绝缘体跃迁。对与温度相关的电阻率的详细分析表明，即使是超低浓度（${ñ}_H\approx {10}^{12}$ 厘米${}^{-2}$）局部化学吸附的H团簇作为传播电子的有效散射中心并限制了平均自由程 ${\mathrm{大号}}_0\propto \mathrm{1个}/\sqrt{{ñ}_H}$。尽管由于吸附而引起的无序性很弱，但发现了强烈的定位。用于破坏系统内相干的激活能量约为30 meV。我们的分析排除了由于氢的吸附而形成的带状绝缘子或什至“不良金属”的情况。