Berlin 2024 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 3: Quantum Dots and Wires: Transport
HL 3.8: Vortrag
Montag, 18. März 2024, 11:45–12:00, EW 202
Coherent Charge Oscillations in a Bilayer Graphene Double Quantum Dot — •Katrin Hecker1,2, Luca Banszerus1,2, Aaron Schäpers1, Samuel Möller1,2, Anton Peters1, Eike Icking1,2, Kenji Watanabe3, Takashi Taniguchi4, Christian Volk1,2, and Christian Stampfer1,2 — 12nd Institute of Physics, RWTH Aachen University, Germany — 2Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Germany — 3Research Center For Functional Materials, NIMS Tsukuba, Japan — 4International Center for Matertial Nanoarchitronics, NIMS Tsukuba, Japan
The coherent dynamics of a quantum mechanical two-level system passing through an anti-crossing of two energy levels can give rise to Landau-Zener-Stückelberg-Majorana (LZSM) interference. LZSM interference spectroscopy has proven to be a fruitful tool to investigate charge noise and charge decoherence in semiconductor quantum dots (QDs). Recently, bilayer graphene has emerged as a promising platform for highly tunable QDs potentially useful for hosting spin and valley qubits. So far, coherent oscillations have not been observed in this system and little is known about charge noise in this material. Here, we report coherent charge oscillations and T2* charge decoherence times in a bilayer graphene double QD. The charge decoherence times are independently measured using LZSM interference and photon assisted tunneling. Both techniques yield T2* average values ranging from 400 to 500 ps. The observation of charge coherence allows to study the origin and spectral distribution of charge noise in future experiments.
Keywords: Bilayer graphene; Charge coherence; Landau-Zener-Stückelberg-Majorana interference; Photon-assisted-tunneling; Quantum dots