On-chip amorphous terahertz topological photonic interconnects.

Valley Hall photonic crystals (VPCs) offer the potential for creating topological waveguides capable of guiding light through sharp bends on a chip, enabling seamless integration with functional components in compact spaces, making them a promising technology for terahertz topological photonic integrated circuits. However, a key limitation for terahertz-scale integrated VPC-based devices has been the absence of arbitrary bend interconnects, as traditional VPC-designs restricted to principal lattice axes (i.e., only 0°, 60°, or 120°) due to crystalline symmetry. Here, we present an on-chip, all-silicon implementation of deformed VPCs that enable robust transmission along arbitrary shapes and bends. Although the lattice is amorphous and lacks long-range periodicity, the topological protection is sustained by short-range order. Furthermore, we show an amorphous lattice functioning as a frequency-dependent router, splitting input signals into two perpendicular output ports. We also demonstrate on-chip terahertz communication, achieving data rates of up to 72 Gbps. Our findings show that amorphous topological photonic crystals enhance interconnect adaptability while preserving performance.