Disorder-tuned thermal transport in quasi-one-dimensional amorphous carbon nanotubes

Thermal transport in low-dimensional materials has attracted significant fundamental and practical interest, as demonstrated by extensive studies of two- and one-dimensional (1D) crystals. In grim contrast, low-dimensional amorphous materials remain largely unexplored. Here, we theoretically explore thermal transport in quasi-1D single-walled amorphous carbon nanotubes (a-CNTs). For both zigzag and armchair a-CNTs, the quantum-corrected thermal conductivity (κ) at room temperature decreases by nearly an order of magnitude as the concentration of Stone-Wales defects increases from 0.01 to 0.08. Spectral analysis reveals the critical impact of the low-frequency vibrational modes. The long but finite mean free path of these modes results in the convergence of κ as the tube length reaches several micrometers. Further, lattice dynamics calculations show that, compared to the transverse acoustic modes, the longitudinal acoustic modes are the primary contributors to κ due to their high group velocity. Our work enriches the understanding of heat transfer in low-dimensional amorphous materials, and paves the way for their potential applications.