Coherent Charge Oscillations in a Bilayer Graphene Double Quantum Dot

arXiv (Cornell University)

Abstract

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 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 $T_2^*$ 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 $T_2^*$ 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.

Authors 10

1. K. Hecker Aachen JARA-FIT and 2nd Institute of Physics

   Forschungszentrum Jülich · Ernst Ruska Centre · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-FIT and 2nd Institute of Physics , RWTH Aachen University , 52074 Aachen , Germany, EU

   Peter Grünberg Institute (PGI-9) , Forschungszentrum Jülich , 52425 Jülich , Germany, EU

   JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

   Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany, EU

2. Luca Banszerus Aachen JARA-FIT and 2nd Institute of Physics

   Forschungszentrum Jülich · Ernst Ruska Centre · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-FIT and 2nd Institute of Physics , RWTH Aachen University , 52074 Aachen , Germany, EU

   Peter Grünberg Institute (PGI-9) , Forschungszentrum Jülich , 52425 Jülich , Germany, EU

   JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

   Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany, EU

3. Aaron Schäpers Aachen JARA-FIT and 2nd Institute of Physics

   RWTH Aachen University

   Affiliation as printed

   JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

4. S. Möller Aachen JARA-FIT and 2nd Institute of Physics

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

   Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany, EU

5. Anton Peters Aachen JARA-FIT and 2nd Institute of Physics

   Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-FIT and 2nd Institute of Physics , RWTH Aachen University , 52074 Aachen , Germany, EU

   JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

6. Eike Icking Aachen JARA-FIT and 2nd Institute of Physics

   Forschungszentrum Jülich · Ernst Ruska Centre · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-FIT and 2nd Institute of Physics , RWTH Aachen University , 52074 Aachen , Germany, EU

   Peter Grünberg Institute (PGI-9) , Forschungszentrum Jülich , 52425 Jülich , Germany, EU

   JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

   Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany, EU

7. Kenji Watanabe

   National Institute for Materials Science

   Affiliation as printed

   Research Center for Functional Materials , National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan

   Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan

8. Takashi Taniguchi

   National Institute for Materials Science

   Affiliation as printed

   International Center for Materials Nanoarchitectonics , National Institute for Materials Science , 1-1 Namiki , Tsukuba 305-0044 , Japan

   International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan

9. Christian Volk Aachen JARA-FIT and 2nd Institute of Physics

   Forschungszentrum Jülich · Ernst Ruska Centre · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-FIT and 2nd Institute of Physics , RWTH Aachen University , 52074 Aachen , Germany, EU

   Peter Grünberg Institute (PGI-9) , Forschungszentrum Jülich , 52425 Jülich , Germany, EU

   JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

   Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany, EU

10. Christoph Stampfer Aachen JARA-FIT and 2nd Institute of Physics

    Forschungszentrum Jülich · Ernst Ruska Centre · Jülich Aachen Research Alliance · RWTH Aachen University

    Affiliation as printed

    JARA-FIT and 2nd Institute of Physics , RWTH Aachen University , 52074 Aachen , Germany, EU

    Peter Grünberg Institute (PGI-9) , Forschungszentrum Jülich , 52425 Jülich , Germany, EU

    JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU

    Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany, EU