1D Superlattice of Tomonaga-Luttinger Liquid Quantum Dots

One-dimensional (1D) quantum systems are renowned for their strong electron-electron interactions and non-Fermi liquid behavior, as captured by Tomonaga-Luttinger Liquid (TLL) theory. In these systems, electronic excitations fractionalize into independent spin and charge modes, manifesting distinct length-dependent energy gaps. However, the minimum length limit for TLL behavior and interactions between 1D TLL systems remain open questions. Here we report the discovery of TLL behavior in mirror twin boundaries (MTBs) in monolayer WSe₂ and a periodic superlattice consisting of TLL quantum dots with lengths as short as 1 nm. By using scanning tunneling microscopy (STM) and differential conductance (dI/dV) mapping, we directly image the spatial distribution and energy evolution of the density of states for a periodic superlattice of TLL quantum dots. We observe strong intra-quantum dot interactions but weak coupling between neighboring quantum dots, maintaining a collective 1D chain behavior. Our results provide a platform for exploring 1D correlated electron systems and have potential applications in quantum information processing and nanoelectronics.