Phys.org  July 27, 2019 Researchers at Stanford University built a hybrid platform that integrates nanomechanical piezoelectric resonators with a microwave superconducting qubit on the same chip. They excited the phonons with resonant pulses and probed the resulting excitation spectrum of the qubit to observe phonon-number-dependent frequency shifts that are about five times larger than the qubit linewidth. The result demonstrated a fully integrated platform for quantum acoustics that combines large couplings, considerable coherence times and excellent control over the mechanical mode structure. With modest experimental improvements, the approach could enable quantum nondemolition measurements of phonons and will lead to quantum […]