Quantum Defects in 2D Transition Metal Dichalcogenides for THz-Technologies

Two-dimensional (2D) transition metal dichalcogenides (TMDs) offer significant advantages for optically addressable defect systems, making them a promising host platform for spin-triplet transition metal impurities with remarkably large zero-field splitting (ZFS) ranging from sub-THz to THz. These defects can serve as the building blocks for quantum information systems and can potentially function as single-photon THz emitters if controlled population inversion is achieved. We employ first-principles materials discovery based on Density Functional Theory (DFT) to identify the most suitable spin-triplet defects in 2D TMDs, followed by constrained DFT combined with group theory analysis to demonstrate the excited-state dynamics and its ability to perform THz qubit operations. Additionally, we propose a novel theoretical design for THz quantum emitters driven by near-infrared excitation. Our research broadens the scope of advancements in quantum information science and lays a robust foundation for their integration with THz technologies.