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-St\"uckelberg-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 developed as a promising platform to host highly tunable QDs potentially useful for hosting spin and valley qubits. So far, in this system no coherent oscillations have been observed 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 measured independently using LZSM interference and photon assisted tunneling. Both techniques yield T2∗ average values in the range of 400 to 500 ps. The observation of charge coherence allows to study the origin and spectral distribution of charge noise in future experiments.
@article{arxiv.2303.10119,
title = {Coherent Charge Oscillations in a Bilayer Graphene Double Quantum Dot},
author = {Katrin Hecker and Luca Banszerus and Aaron Schäpers and Samuel Möller and Anton Peters and Eike Icking and Kenji Watanabe and Takashi Taniguchi and Christian Volk and Christoph Stampfer},
journal= {arXiv preprint arXiv:2303.10119},
year = {2023}
}