Real-Time Feedback Control of Charge Sensing for Quantum Dot Qubits
Takashi Nakajima, Yohei Kojima, Yoshihiro Uehara, Akito Noiri, Kenta Takeda, Takashi Kobayashi, Seigo Tarucha
Abstract
Measuring electrical charge with single-electron resolution is essential for implementing spin qubits in semiconductor quantum dots. Applying quantum dot charge sensors in larger-scale quantum computing devices is being held back because these sensors are easily affected by environmental disturbances, and thus require elaborate tune-up. This study uses a feedback control circuit implemented on a field-programmable gate array to maintain sensor performance in the face of capacitive crosstalk and charge noise. The technique enables rapid tune-up of quantum dot devices and reliable single-shot electron or spin measurement, and will advance the development of large-scale spin-qubit devices.