  We demonstrate a pogo pin package for a superconducting quantum processor
specifically designed with a nontrivial layout topology (e.g., a center qubit
that cannot be accessed from the sides of the chip). Two experiments on two
nominally identical superconducting quantum processors in pogo packages, which
use commercially available parts and require modest machining tolerances, are
performed at low temperature (10 mK) in a dilution refrigerator and both found
to behave comparably to processors in standard planar packages with wirebonds
where control and readout signals come in from the edges. Single- and two-qubit
gate errors are also characterized via randomized benchmarking. More detailed
crosstalk measurements indicate levels of crosstalk less than -40 dB at the
qubit frequencies, opening the possibility of integration with extensible qubit
architectures.
