The physics of a genuine one-dimensional system in which electrons are confined in one direction remains unclear. The actual electronic state of such a genuinely one-dimensional system has not been investigated in previous experiments, for they have all been conducted on quasi-one-dimensional specimens, namely in strongly anisotropic bulk crystals. Conventionally, charge-density waves (CDWs) driven by Fermi surface nesting have been considered to appear in one-dimensional electron-lattice systems. However, the CDW transitions actually observed to date have all occurred in quasi-one-dimensional systems and therefore do not directly indicate a genuine one-dimensional electronic state. We investigated, for the first time, isolated single and double-chain NbS3 samples using the carbon-nanotube-sheath method and discovered CDWs in both systems. In the single-chain, surprisingly, a (1/4)b∗ CDW was observed, in contrast to the (1/3)b∗ CDW that has been observed in bulk samples. In the double-chain, the coexistence of a (1/2)b∗ dimer structure and a (1/3)b∗ CDW was confirmed. This discovery represents a significant advancement in the field of low-dimensional physics, surpassing the limitations of previous studies on bulk systems.
@article{arxiv.2604.16837,
title = {Charge-Density Waves of Single and Double NbS$_{3}$ Chains},
author = {S. Tanda and S. Kashimoto and H. Yamamoto and K. Inagaki and H. Nobukane and Y. Fukuda},
journal= {arXiv preprint arXiv:2604.16837},
year = {2026}
}