Transport at Nanoscale Interfaces Laboratory
Double quantum dots in atomically-precise graphene nanoribbons.
Zhang, J., Qian, L., Borin Barin, G., Chen, P., Müllen, K., Ruffieux, P., Fasel R., Zhang J., Calame M. & Perrin, M. L.
Materials for Quantum Technology, 3(3), 036201 (8 pp.). (2023).
Abstract
Bottom-up synthesized graphene nanoribbons (GNRs) are precise quantum materials, offering a high degree of tunability of their physical properties. While field-effect transistors and single quantum dot (QD) devices have been reported, the fabrication of double QD devices using GNRs remains challenging due to their nanometer-scale dimensions. In this study, we present a multi-gate double QD device based on atomically precise GNRs that are contacted by a pair of single-walled carbon nanotube electrodes. At low temperatures, the device can be tuned with multiple gates and reveals triangular features characteristic for charge transport through a double QD system. From these features, the QD level spacing, as well as the interdot tunnel coupling and lead-dot tunnel couplings are extracted. Double QD systems serve as essential building blocks for developing different types of qubits based on atomically precise GNRs.