Stampfer C, Güttinger J, Hellmüller S, Molitor F, Ensslin K, Ihn T
Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland.
Phys Rev Lett. 2009 Feb 6;102(5):056403. doi: 10.1103/PhysRevLett.102.056403. Epub 2009 Feb 3.
Transport measurements on an etched graphene nanoribbon are presented. It is shown that two distinct voltage scales can be experimentally extracted that characterize the parameter region of suppressed conductance at low charge density in the ribbon. One of them is related to the charging energy of localized states, the other to the strength of the disorder potential. The lever arms of gates vary by up to 30% for different localized states which must therefore be spread in position along the ribbon. A single-electron transistor is used to prove the addition of individual electrons to the localized states. In our sample the characteristic charging energy is of the order of 10 meV, the characteristic strength of the disorder potential of the order of 100 meV.
本文展示了对蚀刻石墨烯纳米带的输运测量结果。结果表明，通过实验可以提取出两个不同的电压标度，它们表征了纳米带中低电荷密度下电导被抑制的参数区域。其中一个与局域态的充电能量有关，另一个与无序势的强度有关。对于不同的局域态，栅极的杠杆臂变化高达30%，因此这些局域态在沿纳米带的位置上必然是分散的。使用单电子晶体管来证明向局域态中逐个添加电子的过程。在我们的样品中，特征充电能量约为10毫电子伏特，无序势的特征强度约为100毫电子伏特。
