Chiroptical Properties and Opto-Twistronic Effect in Self-Assembled Supertwisted Chiral 2D Quantum Materials

Rationally controlling the structures of materials allows us to tune the electronic structures and quantum states of matter, discover new physical properties, thus enabling new applications. We show that the layer stacking, symmetry, and chirality of 2D MX₂ materials can be influenced by the screw dislocations that drive their growth. Furthermore, we achieved systematic interlayer twisting of MX₂ spiral layers due to mismatched geometry between Euclidean crystal lattices and non-Euclidean (curved) surfaces to form chiral 3D moiré superlattices. Such self-assembled twisted spiral superlattices of multilayered WS₂ display a novel opto-twistronic Hall effect driven by structural chirality and coherence length, modulated by the moiré potential of the superlattice. We also observed emerging flatband excitonic emissions and strong chiroptical properties that arise from such supertwisted assembly of MX₂ materials. The ability to assemble different functional 2D materials into supertwisted 3D structures with controllable interlayer twist opens a new dimension for introducing chirality and moiré superlattice in artificial 3D “bulk-like” materials for chiral optoelectronics, twistronics, spin-orbitronic, and quantum applications.