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Coupled Quantum Dots in Bilayer Graphene
journal contribution
posted on 2018-07-09, 00:00 authored by Marius Eich, Riccardo Pisoni, Alessia Pally, Hiske Overweg, Annika Kurzmann, Yongjin Lee, Peter Rickhaus, Kenji Watanabe, Takashi Taniguchi, Klaus Ensslin, Thomas IhnElectrostatic confinement of charge
carriers in bilayer graphene
provides a unique platform for carbon-based spin, charge, or exchange
qubits. By exploiting the possibility to induce a band gap with electrostatic
gating, we form a versatile and widely tunable multiquantum dot system.
We demonstrate the formation of single, double and triple quantum
dots that are free of any sign of disorder. In bilayer graphene, we
have the possibility to form tunnel barriers using different mechanisms.
We can exploit the ambipolar nature of bilayer graphene where pn-junctions
form natural tunnel barriers. Alternatively, we can use gates to form
tunnel barriers, where we can vary the tunnel coupling by more than
2 orders of magnitude tuning between a deeply Coulomb blockaded system
and a Fabry–Pérot-like cavity. Demonstrating such tunability
is an important step toward graphene-based quantum computation.