Highly tunable junctions and non-local Josephson effect in magic-angle graphene tunnelling devices
Name
2011.02500.pdf
Description
Submitted version
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8.34 MB
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Author(s)
Rodan-Legrain, Daniel
Cao, Yuan
Park, Jeong Min
de la Barrera, Sergio C
Randeria, Mallika T
Watanabe, Kenji
Taniguchi, Takashi
Jarillo-Herrero, Pablo
Date Issued
2021
Journal
Nature Nanotechnology
Publisher
Springer Science and Business Media LLC
Citation
Rodan-Legrain, Daniel, Cao, Yuan, Park, Jeong Min, de la Barrera, Sergio C, Randeria, Mallika T et al. 2021. "Highly tunable junctions and non-local Josephson effect in magic-angle graphene tunnelling devices." Nature Nanotechnology, 16 (7).
Version
Original manuscript
Abstract
Magic-angle twisted bilayer graphene (MATBG) has recently emerged as a highly
tunable two-dimensional (2D) material platform exhibiting a wide range of
phases, such as metal, insulator, and superconductor states. Local
electrostatic control over these phases may enable the creation of versatile
quantum devices that were previously not achievable in other single material
platforms. Here, we exploit the electrical tunability of MATBG to engineer
Josephson junctions and tunneling transistors all within one material, defined
solely by electrostatic gates. Our multi-gated device geometry offers complete
control over the Josephson junction, with the ability to independently tune the
weak link, barriers, and tunneling electrodes. We show that these purely 2D
MATBG Josephson junctions exhibit nonlocal electrodynamics in a magnetic field,
in agreement with the Pearl theory for ultrathin superconductors. Utilizing the
intrinsic bandgaps of MATBG, we also demonstrate monolithic edge tunneling
spectroscopy within the same MATBG devices and measure the energy spectrum of
MATBG in the superconducting phase. Furthermore, by inducing a double barrier
geometry, the devices can be operated as a single-electron transistor,
exhibiting Coulomb blockade. These MATBG tunneling devices, with versatile
functionality encompassed within a single material, may find applications in
graphene-based tunable superconducting qubits, on-chip superconducting
circuits, and electromagnetic sensing in next-generation quantum
nanoelectronics.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1038/S41565-021-00894-4
