Abstract
You influence a system by measuring it. This back-action is an important consideration when studying tiny structures in which quantum effects play a crucial role. Researchers now show that quantum interference could provide a way to negate back-action in quantum-dot-qubit circuits. Spin qubits have been successfully realized in electrostatically defined, lateral few-electron quantum-dot circuits1,2,3,4. Qubit readout typically involves spin to charge information conversion, followed by a charge measurement made using a nearby biased quantum point contact1,5,6 (QPC). It is critical to understand the back-action disturbances resulting from such a measurement approach7,8. Previous studies have indicated that QPC detectors emit phonons which are then absorbed by nearby qubits9,10,11,12,13. We report here the observation of a pronounced back-action effect in multiple dot circuits, where the absorption of detector-generated phonons is strongly modified by a quantum interference effect, and show that the phenomenon is well described by a theory incorporating both the QPC and coherent phonon absorption. Our combined experimental and theoretical results suggest strategies to suppress back-action during the qubit readout procedure.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
