All-to-All Connectivity in Superconducting Qubits via Metamaterial-Mediated Interactions

arXiv:2611.01180v1 Announce Type: new Abstract: We show that encoding superconducting qubits as dual-rail or spin-locked transmons lets a metamaterial waveguide couple them all-to-all while suppressing the spurious entanglement that burdens shared-mode architectures, a step toward the non-local connectivity that quantum low-density parity-check codes require. In a bare-transmon architecture, the dispersive coupling between each populated mode and every idle qubit attached to it entangles spectators with the gate, and cancelling it by dynamical decoupling lengthens every gate. The encoding suppresses this coupling at the hardware level, from second to fourth order in the inverse qubit--mode detuning.