Benchmarking bosonic modes with randomized displacements

We proposed, analysed, and experimentally demonstrated a new randomized benchmarking protocol to characterise, verify, and validate bosonic modes. Our bosonic randomized benchmarking (BRB) protocol performs randomized, controlled displacements in the phase space. We developed theory models for leading noise sources and found that the measured fidelities are well approximated by Gamma-distributions, whose key parameters are intimately tied to the noise characteristics. We applied the BRB protocol to characterize a bosonic mode in the vibrational motion of a trapped ion and were able to extract the correlation, strength and source of the noise with few measurements. The protocol enables an efficient and hardware-agnostic way to identify dominant noise processes and extract key noise characteristics. It can be useful for applications that use bosonic modes, such as continuous variable quantum computing and quantum sensing.