Biomaterial Database

Tunneling Spectroscopy in Carbon Nanotube-Hexagonal Boron Nitride-Carbon Nanotube Heterojunctions. 2020

Sihan Zhao, and SeokJae Yoo, and Sheng Wang, and Bosai Lyu, and Salman Kahn, and Fanqi Wu, and Zhiyuan Zhao, and Dingzhou Cui, and Wenyu Zhao, and Yoseob Yoon, and M Iqbal Bakti Utama, and Wu Shi, and Kenji Watanabe, and Takashi Taniguchi, and Michael F Crommie, and Zhiwen Shi, and Chongwu Zhou, and Feng Wang

Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States.

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.