Front-Line Research on “Cryogenic Digital Circuits for Peripheral Circuits of Quantum Computer”

Research on quantum computers is actively carried out all over the world due to their high computing performance utilizing quantum superposition states in quantum bits (qubits). Currently, qubits based on solid-state devices using superconductor or silicon devices are the most promising because of its controllability and scalability. These devices are usually placed at cryogenic temperatures, around several mK, to reduce the thermal noise for the qubit. One obstacle for these systems is the necessity of a large number of control and readout microwave lines to connect the qubits with room temperature electronics. To overcome this issue, much research on cryogenic interface circuits to connect qubits and room-temperature electronics has recently proceeded. The investigative committee of the Institute of Electrical Engineers of Japan investigated the front-line research on this topic. In this paper, we summarized the investigation results.