Inside these materials, strange quantum ripples called Higgs modes can appear. Scientists at Ames National Laboratory and Iowa State University have discovered a surprising “quantum echo” in a superconducting material, a type of quantum reverberation that hadn’t been observed before. They discovered a novel type of quantum echo, called the “Higgs echo,” in superconducting niobium materials used in quantum computing circuits. This research demonstrates that scientists can now control and observe quantum coherence, the delicate balance of quantum states, within superconductors. “Understanding and controlling these unique quantum echoes brings us a step closer to practical quantum computing and advanced quantum sensing technologies,” said Wang.