Revealing the Stability and Conductivity of 1D Structures in 2D Semiconducting Lattices

Recent experiments show that one-dimensional (1D) structures in two-dimensional (2D) semiconducting lattices exhibit either metallic or semiconducting behavior, but the underlying mechanisms are unclear. Our theoretical model predicts that couplings between the 1D structures and the 2D lattices via elastic support and electron transfer play crucial roles. The predicted phase diagram shows that elastic support stabilizes the metallic phase when electron transfer is present. Validated by first-principles calculations on MoS₂, we discover two new types of metallic grain boundaries. Our theory provides a robust framework for designing stable 1D metallic structures.