Mid-circuit correction of correlated phase errors using an array of spectator qubits

In our latest work on the dual-species atom array we show how two atomic qubit arrays can help each other out. We use our cesium atoms as an array of spectator qubits that sense the noise environment and estimate phase errors that are caused by this noise. This information is then used to correct correlated errors in real time on our rubidium array of data qubits. We show that we can mitigate noise and preserve coherence using this feed-forward protocol. For this to work, we developed mid-circuit readout of the spectator qubits without perturbing the data qubits, real-time processing and feed-forward, and coherent reloading. Find out more here.