Zhao Sihan, Yoo SeokJae, Wang Sheng, Lyu Bosai, Kahn Salman, Wu Fanqi, Zhao Zhiyuan, Cui Dingzhou, Zhao Wenyu, Yoon Yoseob, Utama M Iqbal Bakti, Shi Wu, Watanabe Kenji, Taniguchi Takashi, Crommie Michael F, Shi Zhiwen, Zhou Chongwu, Wang Feng
Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States.
Department of Physics, Korea University, Seoul 02841, Republic of Korea.
Nano Lett. 2020 Sep 9;20(9):6712-6718. doi: 10.1021/acs.nanolett.0c02585. Epub 2020 Aug 11.
Electron tunneling spectroscopy is a powerful technique to probe the unique physical properties of one-dimensional (1D) single-walled carbon nanotubes (SWNTs), such as the van Hove singularities in the density of states or the power-law tunneling probability of a Luttinger liquid. However, little is known about the tunneling behavior between two 1D SWNTs over a large energy spectrum. Here, we investigate the electron tunneling behavior between two crossed SWNTs across a wide spectral window up to 2 eV in the unique carbon nanotube-hexagonal boron nitride-carbon nanotube heterojunctions. We observe many sharp resonances in the differential tunneling conductance at different bias voltages applied between the SWNTs. These resonances can be attributed to elastic tunneling into the van Hove singularities of different 1D subbands in both SWNTs, and they allow us to determine the quasi-particle bandgaps and higher-lying 1D subbands in SWNTs on the insulating substrate.
电子隧穿光谱是一种探测一维（1D）单壁碳纳米管（SWNTs）独特物理性质的强大技术，例如态密度中的范霍夫奇点或卢廷格液体的幂律隧穿概率。然而，对于两个1D SWNTs在大能量谱上的隧穿行为知之甚少。在这里，我们研究了在独特的碳纳米管 - 六方氮化硼 - 碳纳米管异质结中，两个交叉的SWNTs之间跨越高达2 eV的宽光谱窗口的电子隧穿行为。我们观察到在SWNTs之间施加的不同偏置电压下，微分隧穿电导中有许多尖锐的共振。这些共振可归因于弹性隧穿到两个SWNTs中不同1D子带的范霍夫奇点，并且它们使我们能够确定绝缘衬底上SWNTs中的准粒子带隙和更高的1D子带。
