Qu&Co comments on this publication:
Coupling between superconducting qubits is typically controlled not by changing the qubit-qubit coupling constant, but by suppressing the coupling by detuning their transition frequency. This approach becomes much more difficult with a high number of qubits, due to the ever-more crowded transition-frequency spectrum. In this paper, Casparis et al. demonstrate an alternative coupling scheme, in the form of a voltage controlled quantum-bus with the ability to change the effective qubit-qubit coupling by a factor of 8 between the on- and off-states without causing significant qubit decoherence.