Radio-frequency charge detection on graphene electron-hole double quantum dots
Katrin Hecker, Samuel Möller, Hubert Dulisch, Şiyar Duman, Leon Stecher, Lucca Valerius, Tobias Deußen, Saketh Ravuri, Kenji Watanabe, Takashi Taniguchi, Florian Libisch, Christian Volk, Christoph Stampfer
公開日: 2025/9/15
Abstract
High-fidelity detection of charge transitions in quantum dots (QDs) is a key ingredient in solid state quantum computation. We demonstrate high-bandwidth radio-frequency charge detection in bilayer graphene quantum dots (QDs) using a capacitively coupled quantum point contact (QPC). The device design suppresses screening effects and enables sensitive QPC-based charge readout. The QPC is arranged to maximize the readout contrast between two neighboring, coupled electron and hole QDs. We apply the readout scheme to a single-particle electron-hole double QD and demonstrate time-resolved detection of charge states as well as magnetic field dependent tunneling rates. This promises a high-fidelity readout scheme for individual spin and valley states, which is important for the operation of spin, valley or spin-valley qubits in bilayer graphene.