Hogg, MR; House, MG; Pakkiam, P; Simmons, MY
Future large-scale quantum computing devices based on semiconductor spin qubits require multiplexed microwave control signals for manipulation and readout of the qubits. However, interfacing these control signals between room temperature and cryogenic temperatures where the qubits operate is a complex technical challenge. Here, we show a microwave modulator based on a nanoengineered semiconductor quantum dot that is designed to operate at millikelvin temperatures alongside the qubits. We operate the modulator as a mixer and a frequency multiplier over a bandwidth of up to 25 GHz. We estimate the power dissipation when driving quantum gates using frequency-up-converted signals under realistic experimental conditions to be 4 pW, highly compatible with the cooling powers available in current commercial dilution refrigerators. The device is fabricated in silicon using atomic precision lithography, providing a pathway toward combining qubits and classical control functionality on the same integrated chip.