Enhancing quantum I/O: proven transmon qubit performance with scalable I/O over flexible integrated circuits part 2/2

Transmon quantum computers have reached a significant milestone in the field. Many research groups are building quantum processors with over 10 qubits, some even working towards 1.000+-qubit systems. Future steps require both higher qubit count as well as longer coherence times.

Connecting room temperature equipment to the QPU is key for these two challenges. Scaling these interconnects requires high signal integrity, low thermal load within a small space. To that end, we present flexible planar multichannel microwave circuits (flex) with a combination of integrated resistive, and superconducting structures to link control- and read-out electronics to the qubits at milliKelvin temperatures.

In the second part of this two-part presentation, we present an overview of scaling challenges and introduce a solution compatible with cryogenic industry standards based on this flex technology. Also, we discuss the limitations of the flex technology.