Circuit cavity electromechanics in the strong-coupling regime

The drive towards observing quantum effects in macroscopic mechanical systems could lead to new insights in quantum-limited measurements and help to test fundamental questions regarding the impossible consequences of quantum physics at a macroscopic scale. To obtain sufficiently long-lived mechanical states, the usual approach is to couple a mechanical oscillator to an electromagnetic resonance in a cavity. Teufel et al. present a new design for such a system in which a free-standing flexible aluminium membrane (like a drum) is incorporated in a cavity defined by a superconducting circuit, and which demonstrates a coupling strength that is two orders of magnitude higher than that achieved before. The approach shows the way to observing long-lived quantum states that could survive for hundreds of microseconds.