QuTHERA is a project for developing single-photon detectors for terahertz radiation based on superconducting qubits. The project is in an early planning stage.

The animation below shows the envisioned detection chain, using the search for dark-photon dark matter as an example. A dark photon converts at a gold-plated copper hemisphere into a terahertz photon. Since the photons are emitted normal to the surface, they converge at the center of the dish, where a silicon lens couples them onto a qubit chip. The qubit island acts as an antenna and delivers the photon to the Josephson junction, where it breaks a Cooper pair. The resulting quasiparticle changes the charge parity of the island, which shifts the qubit resonance and is detected in the transmission of a microwave probe tone.