Quasiparticle and superfluid dynamics in Magic-Angle Graphene

Abstract Magic-Angle Twisted Bilayer Graphene (MATBG) shows a wide range of correlated phases which are electrostatically tunable. Despite a growing knowledge of the material, there is yet no consensus on the microscopic mechanisms driving its superconducting phase. A major obstacle to progress in t...

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Main Authors: Elías Portolés, Marta Perego, Pavel A. Volkov, Mathilde Toschini, Yana Kemna, Alexandra Mestre-Torà, Giulia Zheng, Artem O. Denisov, Folkert K. de Vries, Peter Rickhaus, Takashi Taniguchi, Kenji Watanabe, J. H. Pixley, Thomas Ihn, Klaus Ensslin
Format: Article
Language:English
Published: Nature Portfolio 2025-05-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-58325-0
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author Elías Portolés
Marta Perego
Pavel A. Volkov
Mathilde Toschini
Yana Kemna
Alexandra Mestre-Torà
Giulia Zheng
Artem O. Denisov
Folkert K. de Vries
Peter Rickhaus
Takashi Taniguchi
Kenji Watanabe
J. H. Pixley
Thomas Ihn
Klaus Ensslin
author_facet Elías Portolés
Marta Perego
Pavel A. Volkov
Mathilde Toschini
Yana Kemna
Alexandra Mestre-Torà
Giulia Zheng
Artem O. Denisov
Folkert K. de Vries
Peter Rickhaus
Takashi Taniguchi
Kenji Watanabe
J. H. Pixley
Thomas Ihn
Klaus Ensslin
author_sort Elías Portolés
collection DOAJ
description Abstract Magic-Angle Twisted Bilayer Graphene (MATBG) shows a wide range of correlated phases which are electrostatically tunable. Despite a growing knowledge of the material, there is yet no consensus on the microscopic mechanisms driving its superconducting phase. A major obstacle to progress in this direction is that key thermodynamic properties, such as specific heat, electron-phonon coupling and superfluid stiffness, are challenging to measure due to the 2D nature of the material and its relatively low energy scales. Here, we use a gate-defined, radio frequency-biased, Josephson junction to probe the electronic dynamics of MATBG. We demonstrate evidence for two processes determining the low-frequency dynamics across the phase diagram: thermalization of electronic quasiparticles through phonon scattering and inductive response of the superconducting condensate. A phenomenological approach allows us to relate the experimentally observed dynamics to several thermodynamic properties of MATBG, including electron-phonon coupling and superfluid stiffness. Our findings support anisotropic or nodal superconductivity in MATBG and demonstrate a broadly applicable method for studying properties of 2D materials with out-of-equilibrium nanodevice dynamics.
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spelling doaj-art-e703569aeb32416a880a7d5860473d3a2025-08-20T03:09:20ZengNature PortfolioNature Communications2041-17232025-05-011611910.1038/s41467-025-58325-0Quasiparticle and superfluid dynamics in Magic-Angle GrapheneElías Portolés0Marta Perego1Pavel A. Volkov2Mathilde Toschini3Yana Kemna4Alexandra Mestre-Torà5Giulia Zheng6Artem O. Denisov7Folkert K. de Vries8Peter Rickhaus9Takashi Taniguchi10Kenji Watanabe11J. H. Pixley12Thomas Ihn13Klaus Ensslin14Laboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichDepartment of Physics, University of ConnecticutLaboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichResearch Center for Materials Nanoarchitectonics, National Institute for Materials ScienceResearch Center for Electronic and Optical Materials, National Institute for Materials ScienceDepartment of Physics and Astronomy, Center for Materials Theory, Rutgers UniversityLaboratory for Solid State Physics, ETH ZurichLaboratory for Solid State Physics, ETH ZurichAbstract Magic-Angle Twisted Bilayer Graphene (MATBG) shows a wide range of correlated phases which are electrostatically tunable. Despite a growing knowledge of the material, there is yet no consensus on the microscopic mechanisms driving its superconducting phase. A major obstacle to progress in this direction is that key thermodynamic properties, such as specific heat, electron-phonon coupling and superfluid stiffness, are challenging to measure due to the 2D nature of the material and its relatively low energy scales. Here, we use a gate-defined, radio frequency-biased, Josephson junction to probe the electronic dynamics of MATBG. We demonstrate evidence for two processes determining the low-frequency dynamics across the phase diagram: thermalization of electronic quasiparticles through phonon scattering and inductive response of the superconducting condensate. A phenomenological approach allows us to relate the experimentally observed dynamics to several thermodynamic properties of MATBG, including electron-phonon coupling and superfluid stiffness. Our findings support anisotropic or nodal superconductivity in MATBG and demonstrate a broadly applicable method for studying properties of 2D materials with out-of-equilibrium nanodevice dynamics.https://doi.org/10.1038/s41467-025-58325-0
spellingShingle Elías Portolés
Marta Perego
Pavel A. Volkov
Mathilde Toschini
Yana Kemna
Alexandra Mestre-Torà
Giulia Zheng
Artem O. Denisov
Folkert K. de Vries
Peter Rickhaus
Takashi Taniguchi
Kenji Watanabe
J. H. Pixley
Thomas Ihn
Klaus Ensslin
Quasiparticle and superfluid dynamics in Magic-Angle Graphene
Nature Communications
title Quasiparticle and superfluid dynamics in Magic-Angle Graphene
title_full Quasiparticle and superfluid dynamics in Magic-Angle Graphene
title_fullStr Quasiparticle and superfluid dynamics in Magic-Angle Graphene
title_full_unstemmed Quasiparticle and superfluid dynamics in Magic-Angle Graphene
title_short Quasiparticle and superfluid dynamics in Magic-Angle Graphene
title_sort quasiparticle and superfluid dynamics in magic angle graphene
url https://doi.org/10.1038/s41467-025-58325-0
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