Rapid High-Fidelity Multiplexed Readout of Superconducting Qubits

The duration and fidelity of qubit readout is a critical factor for applications in quantum information processing as it limits the fidelity of algorithms, which reuse qubits after measurement or apply feedback based on the measurement result. In this talk we discuss the results of a fast multiplexed readout experiment performed on five qubits with readout resonators populated for less than 200 ns. We find that the probability of assigning the individual qubit to be in the state we intended to prepare, is above 95% for all five measured qubits. In addition, the data shows that individual Purcell filters used in this experiment lead to reduced measurement induced dephasing of the qubits we did not intend to measure.