The existence of pure boron nanotubes (BNTs) has been proposed more than ten years ago . The BNTs are predicted to have a metallic conductivity independent of their diameter and chiral angle [1-3], in contrast to the well-studied carbon nanotubes. This property makes BNTs good candidates for nanometer-scale conducting elements of future electronic devices. Recent experimental work on BNTs  has provided the first evidence for their metallic behavior. Nevertheless, there are still many open questions on the physical properties of BNTs which need to be answered on both the theoretical and experimental sides. In our work we theoretically investigate the electronic structure and transport properties of large-diameter BNTs of different structures and chiralities. Our results are in agreement with recent experimental findings, and a method to control the electron transport in BNTs is proposed.
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