Timing Controller for a Superconductor Microwave Switch using Adiabatic Quantum Flux Parametron Circuits

抄録

We are developing a microwave pulse generator, whose pulse width and amplitude can be arbitrarily controlled, to manipulate superconducting quantum computing systems. The proposed microwave pulse generator is made using superconducting circuits. It can be placed at a 4.2 K or lower temperature stages to control a large-scale quantum computing system effectively. One of the key components of the microwave pulse generator is the timing controller, which generates trigger pulses for the microwave switch to start and stop the microwave irradiation. The target frequency of the microwave is 5 GHz, and the timing controller has to generate trigger pulses with a time resolution of several nanoseconds. We designed a 4-bit timing controller using an adiabatic quantum flux parametron (AQFP) circuit, which is extremely energy-efficient superconducting logic. The designed timing controller derives two trigger pulses, start and stop, to the microwave switch at the timing designated by digital data. We implemented the AQFP timing controller using the AIST HSTP process and demonstrated its operation at 1 GHz. Its power dissipation was estimated as about 1.25×10^-9 W at 1 GHz.