Journal Article THz on‐chip cavity THz topological photonic integrated circuits calibration‐free biosensing chirality deep‐learning heterogeneous interfaces interface topology engineering metasurface non‐volatile reconfiguration on‐chip on‐chip terahertz interconnects on‐chip topological cavity optothermal control phase‐change material radiation loss supercoupled cavity terahertz terahertz interfacial waveguide terahertz topological photonic integrated circuit terahertz topological photonic integrated circuits topological cavity topological photonics ultrahigh Q‐factor ultralow‐loss waveguides