Crosstalk remains a major issue

Crosstalk remains a major issue in the design of microwave drive lines for fast single qubit control. Microwave drive lines for qubit control must be placed sufficiently far from the qubit to limit the qubit-drive line coupling and the resulting decrease in qubit lifetimes via the purcell effect. However, this generally leads to an increase in crosstalk between qubit drive lines. Electromagnetic simulations of the new 10-qubit processor have shown that we must be willing to accept -15 dB of crosstalk between nearest neighbor qubits in order to maintain purcell limited qubit lifetimes in excess of 100 us.