Simulation of Readout in Circuit QED using Tensor Processing Units

Tensor Processing Units (TPUs) are application specific integrated circuits (ASICs) developed by Google to support large-scale machine learning tasks, but they can also be used for other computational tasks. In this work, we repurpose TPUs for classically simulating superconducting devices used as quantum hardware. Specifically, we consider the simulation of a transmon coupled to a resonator in a number of parameter regimes. The ability of TPU's to multiply extremely large matrices allows us to explore the structural instabilities of the transmon in the presence of hundreds of energy quanta, outside the capability of other traditional classical hardware. We establish the onset of this structural instability and subsequently establish bounds on readout drive power.