Collective quantum coherence and subband redistribution in artificially assembled nanotube arrays

Artificial assembly of one-dimensional ballistic conductors into a two-dimensional (2D) system can provide an ideal platform to study coherent electronic coupling and designable physical properties. However, systematic investigations of both the coupling and ballistics in such artificially assembled systems remain scarce. Here, we report collective quantum coherence in a quasi-2D film consisting of well-aligned single-walled carbon nanotubes (CNTs) with intertube coupling. The conductance plateaus in the quasi-ballistic regime demonstrate subband occupations of hundreds of CNTs in a collective manner. The experimental observations agree with density functional theory simulations considering subband redistribution with intertube coupling. Finally, we summarize the quantum coherent transport for multichannel coupled systems in distinct regimes. These results open an avenue towards exploring engineered artificial systems for coherent electronic devices and hold potential for the development of novel high-performance and quantum nanoelectronics.