  Here, we report the experimental demonstration of a novel multi-mode linear
bus interferometer (LBI) coupler in a six qubit superconducting quantum
processor. A key feature of this coupler is an engineered multi-path
interference which eliminates transverse coupling between qubits over a wide
frequency range. This negligible static coupling is achieved without any flux
bias tuning, and greatly reduces the impact of qubit frequency collisions. We
achieve good simultaneous single qubit gate operation and low ZZ rates (below
600 Hz) across the device without staggering qubit frequencies, even in cases
where qubits are as close as 10 MHz. Multi-qubit interactions are still
possible through the coupler using microwave-driven resonator induced phase
gates, which we utilize to demonstrate simultaneous two qubit gates with
fidelities as high as 99.4%
