Readout of a qubit array via a single transmission line

Frequency-selective readout for superconducting qubits opens up the way towards scaling qubit circuits without increasing the number of measurement lines. Here we demonstrate the readout of an array of 7 flux qubits located on the same chip using a single measurement line. Each qubit is placed near an individual λ/4 resonator which, in turn, is coupled to a common microwave transmission line. We performed spectroscopy and coherent manipulation of all qubits and determined their parameters in a single measurement run.