Photon-Pressure with an Effective Negative Mass Microwave Mode

Abstract: Harmonic oscillators belong to the most fundamental concepts in physics and are central to many current research fields such as circuit QED, cavity optomechanics and photon-pressure systems. Here, we engineer a microwave mode in a superconducting LC circuit that mimics the dynamics of a negative mass oscillator, and couple it via photon-pressure to a second low-frequency circuit. We demonstrate that the effective negative mass dynamics lead to an inversion of dynamical backaction and to sideband-cooling of the low-frequency circuit by a blue-detuned pump field, which can be intuitively understood by the inverted energy ladder of a negative mass oscillator.