The formation and properties of a supersolid structure in a three-component ultracold Bose gas mixture at $T=0$ are investigated theoretically. The system consists of ${}^{23}\mathrm{Na}$, ${}^{39}\mathrm{K}$, and ${}^{41}\mathrm{K}$ atomic species, in which the binary mixtures of (${}^{23}\mathrm{Na},{}^{39}\mathrm{K}$) and (${}^{39}\mathrm{K},{}^{41}\mathrm{K}$) can form self-bound quantum droplets stabilized by quantum fluctuations. Two such droplets can bind together by the shared ${}^{39}\mathrm{K}$ component, forming a stable “dimer” structure, which displays vibrational modes analogous to a classical diatomic molecule. A simple protocol is proposed to create a stable linear chain formed by periodic repetition of this basic building block, i.e., an alternating sequence of (${}^{23}\mathrm{Na},{}^{39}\mathrm{K}$) and (${}^{39}\mathrm{K},{}^{41}\mathrm{K}$) droplets. This structure exhibits both periodic density modulations from the droplet ordering and global phase coherence due to the shared ${}^{39}\mathrm{K}$ component, satisfying the criteria for supersolidity. This expands the class of known supersolids by adding a system where mediated binding—rather than intrinsic long-range interactions or engineered band structures as in previously known supersolids—is the key organizing principle, thereby offering alternative directions for both theory and experiment. The low-energy excitation spectrum, probed by density perturbations, identifies modes corresponding to droplet vibrations close to the ones expected from a classical diatomic chain, coexisting with low-energy superfluid (Goldstone-type) modes.

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• Cold atoms & matter waves