Observation of Coulomb blockade in nanostructured epitaxial bilayer graphene on SiC
Observation of Coulomb blockade in nanostructured epitaxial bilayer graphene on SiC
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DOI：
10.1016/j.carbon.2017.04.019
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发表时间：
2017-03
期刊：
影响因子：
10.9
通讯作者：
C. Chua;A. Lartsev;Jing-jing Sui;V. Panchal;R. Puddy;C. Richardson;Charles G. Smith;T. Janssen
中科院分区：
文献类型：
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作者：
C. Chua;A. Lartsev;Jing-jing Sui;V. Panchal;R. Puddy;C. Richardson;Charles G. Smith;T. Janssen
我们研究了电子输运的纳米结构图案的双层石墨烯补丁外延生长在SiC作为掺杂，磁场和温度的函数。远离电中性的传输仅受到局部侧栅引起的载流子浓度变化的微弱调制。在接近电荷中性的低n型掺杂下，电子输运类似于剥离的石墨烯纳米带中的电子输运，并且通过单个电子通过库仑阻塞岛的网络的隧穿来很好地描述。在外加磁场的影响下，库仑阻塞共振在平均能量附近波动，并且差距作为磁场的函数而收缩。然而，在电荷中性时，传导对外部磁场不太敏感。在这个制度中，我们还观察到一个更强的抑制T* 以下的电导，我们解释为一个迹象，打破层间对称性或强波动的边缘/潜在的障碍。
We study electron transport in nanostructures patterned in bilayer graphene patches grown epitaxially on SiC as a function of doping, magnetic field, and temperature. Away from charge neutrality transport is only weakly modulated by changes in carrier concentration induced by a local side-gate. At low n-type doping close to charge neutrality, electron transport resembles that in exfoliated graphene nanoribbons and is well described by tunnelling of single electrons through a network of Coulomb-blockaded islands. Under the influence of an external magnetic field, Coulomb blockade resonances fluctuate around an average energy and the gap shrinks as a function of magnetic field. At charge neutrality, however, conduction is less insensitive to external magnetic fields. In this regime we also observe a stronger suppression of the conductance below T*, which we interpret as a sign of broken interlayer symmetry or strong fluctuations in the edge/potential disorder.