  High-fidelity quantum state transfer and remote entanglement between
superconducting fixed-frequency qubits have not yet been realized. In this
study, we propose an alternative remote cross-resonance gate. Considering
multiple modes of a superconducting coaxial cable connecting qubits, we must
find conditions under which the cross-resonance gate operates with a certain
accuracy even in the presence of qubit frequency shifts due to manufacturing
errors. For 0.25- and 0.5-m cables, remote cross-resonance gates with a
concurrence of $>99.9\%$ in entanglement generation are obtained even with
$\pm$10-MHz frequency shifts. For a 1-m cable with a narrow mode spacing, a
concurrence of 99.5\% is achieved by reducing the coupling between the qubits
and cable. The optimized echoed raised-cosine pulse duration is 150--400 ns,
which is similar to the operation time of cross-resonance gates between
neighboring qubits on a chip. The dissipation through the cable modes does not
considerably affect the obtained results. Such high-precision quantum
interconnects pave the way not only for scaling up quantum computer systems but
also for nonlocal connections on a chip.
