First self-powered quantum microwave signal achieved in experiment

Researchers from Vienna University of Technology (TU Wien) and Okinawa Institute of Science and Technology (OIST) have experimentally demonstrated the first self-induced superradiant masing—microwave signal generation without external driving forces. Superradiance, a quantum optics phenomenon where atoms or quantum dots emit intense, coherent light pulses collectively, was traditionally associated with energy loss and short bursts. However, the team observed a novel behavior where quantum particles, specifically electron spins in nitrogen-vacancy (NV) centers within diamond ensembles, self-sustain long-lived, stable microwave pulses through intrinsic spin–spin interactions. This self-organization from seemingly disordered spin interactions produces a coherent microwave signal, revealing a fundamentally new mode of collective quantum behavior. The discovery challenges previous assumptions that interactions among quantum particles disrupt coherence, showing instead that these interactions can fuel and maintain quantum emission. Large-scale computational simulations confirmed that spin interactions continually repopulate energy levels, sustaining the superradiant reaction over extended periods. This breakthrough opens new avenues for