ETH Researchers Demonstrate 5-Meter-Long Microwave Quantum Link

In the future, quantum links will connect clusters of quantum computers to form a local network. These links will need to support quantum mechanical superposition states (states that contain the logical values 0 and 1 at the same time). The longest such link to date, based on microwaves, has been built at ETH Zurich, in the laboratory of professor Andreas Wallraff. The microwave quantum link is 5 meters long. “The challenge was to connect two of those superconducting quantum chips in such a way as to be able to exchange superposition states between them with minimal decoherence,” researcher Philipp Kurpiers said. To suppress decoherence (the thermal perturbations that can cause a quantum state to lose its...