Strong magnetomechanical coupling Part 1*

The possibility to operate mechanical systems close to the quantum regime has become central in both fundamental and applied science. A key parameter here is how strongly photons will impact the mechanics. The microwave regime offers the opportunity to achieve large couplings towards a regime where the coupling rate becomes the dominant time scale. In our ongoing experimental efforts to reach this single-photon strong coupling regime, we developed an approach based on a mechanical oscillator inductively coupled to a superconducting circuit. We place a NdFeB micromagnet on the tip of an AFM cantilever and align it on top of the SQUID of a tunable 3D microstrip resonator. When flux sensitive, the motion of the cantilever will result in a change in resonance frequency of the microstrip resonator, similar to typical cavity optomechanical setups. Varying the external flux allows us to tune the coupling strength from virtually zero to higher values, reaching single photon strong cooperativity, allowing for cooling with a single photon. Improving our current design, we hope to reach single photon strong coupling, allowing the quantum control of massive mechanical resonators.