Tunable coupler to fully decouple superconducting qubits

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A major bottleneck of current NISQ hardware is low fidelity of 2 qubit gates. A component to improve this is the possibility to completely switch off interactions between qubits. In our pre-print we derive conditions for the coupler to suppress all parasitic interactions, i.e. state delocalization and ZZ-crosstalk. We then develop a coupler model for Transmons that meets these requirements and show numerically that the qubits decouple completely. Thus, the influence of spectator qubits on an adjacent qubit pair undergoing a gate sequence can be strongly suppressed, so that gate fidelities in an integrated system can be brought to the level of isolated 2 qubit gates.