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Terahertz photocurrent probe of quantum geometry and interactions in magic-angle twisted bilayer graphene

AbstractMoiré materials represent strongly interacting electron systems bridging topological and correlated physics. Despite notable advances, decoding wavefunction properties underlying the quantum geometry remains challenging. Here we utilize polarization-resolved photocurrent measurements to probe magic-angle twisted bilayer graphene, leveraging its sensitivity to the Berry connection that encompasses quantum ‘textures’ of electron wavefunctions. Using terahertz light resonant with optical transitions of its flat bands, we observe bulk photocurrents driven by broken symmetries and reveal the interplay between electron interactions and quantum geometry. We observe inversion-breaking gapped states undetectable through quantum transport, sharp changes in the polarization axes caused by interaction-induced band renormalization and recurring photocurrent patterns at integer filling factors of the moiré unit cell that track the evolution of quantum geometry through the cascade of phase transitions. The large and tunable terahertz response intrinsic to flat-band systems offers direct insights into the quantum geometry of interacting electrons and paves the way for innovative terahertz quantum technologies.

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Fig. 1: Polarization-dependent THz photocurrents in TBG.Fig. 2: ν dependence of α in TBG.Fig. 3: Hartree-interaction-induced THz photocurrents.Fig. 4: Temperature dependence of photoresponse and α.Fig. 5: Photocurrent cascade in commensurate TBG aligned to hBN with a supermoiré potential.

Data availability

The data that support the plots within this paper are available via Zenodo at https://doi.org/10.5281/zenodo.14882592 (ref. 56). Additional data including those from the Supplementary Information are available from the corresponding authors upon request.

ReferencesCao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).Article 

CAS 

PubMed 

Google Scholar 

Cao, Y. et al. Correlated insulator behaviour at half-filling in magic-angle graphene superlattices. Nature 556, 80–84 (2018).Article 

CAS 

PubMed 

Google Scholar 

Andrei, E. Y. & MacDonald, A. H. Graphene bilayers with a twist. Nat. Mater. 19, 1265–1275 (2020).Article 

CAS 

PubMed 

Google Scholar 

Sharpe, A. L. et al. Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene. Science 365, 605–608 (2019).Article 

CAS 

PubMed 

Google Scholar 

Serlin, M. et al. Intrinsic quantized anomalous Hall effect in a moiré heterostructure. Science 367, 900–903 (2020).Article 

CAS 

PubMed 

Google Scholar 

Stepanov, P. et al. Competing zero-field chern insulators in superconducting twisted bilayer graphene. Phys. Rev. Lett. 127, 197701 (2021).Article 

CAS 

PubMed 

Google Scholar 

Andrei, E. Y. et al. The marvels of moiré materials. Nat. Rev. Mater. 6, 201–206 (2021).Article 

CAS 

Google Scholar 

Tschirhart, C. L. et al. Imaging orbital ferromagnetism in a moiré Chern insulator. Science 372, 1323–1327 (2021).Article 

CAS 

PubMed 

Google Scholar 

Grover, S. et al. Chern mosaic and Berry-curvature magnetism in magic-angle graphene. Nat. Phys. 18, 885–892 (2022).Article 

CAS 

Google Scholar 

Cea, T., Pantaleón, P. A. & Guinea, F. Band structure of twisted bilayer graphene on hexagonal boron nitride. Phys. Rev. B 102, 155136 (2020).Article 

CAS 

Google Scholar 

Kazmierczak, N. P. et al. Strain fields in twisted bilayer graphene. Nat. Mater. 20, 956–963 (2021).Article 

CAS 

PubMed 

Google Scholar 

Carr, S., Fang, S., Zhu, Z. & Kaxiras, E. Exact continuum model for low-energy electronic states of twisted bilayer graphene. Phys. Rev. Res. 1, 13001 (2019).Article 

CAS 

Google Scholar 

Ma, Q., Krishna Kumar, R., Xu, S.-Y., Koppens, F. H. L. & Song, J. C. W. Photocurrent as a multiphysics diagnostic of quantum materials. Nat. Rev. Phys. 5, 170–184 (2023).Article 

Google Scholar 

Ma, Q., Grushin, A. G. & Burch, K. S. Topology and geometry under the nonlinear electromagnetic spotlight. Nat. Mater. 20, 1601–1614 (2021).Article 

CAS 

PubMed 

Google Scholar 

Dai, Z. & Rappe, A. M. Recent progress in the theory of bulk photovoltaic effect. Chem. Phys. Rev. 4, 11303 (2023).Article 

CAS 

Google Scholar 

Nakamura, M. et al. Shift current photovoltaic effect in a ferroelectric charge-transfer complex. Nat. Commun. 8, 281 (2017).Article 

CAS 

PubMed 

PubMed Central 

Google Scholar 

Ma, C. et al. Intelligent infrared sensing enabled by tunable moiré quantum geometry. Nature 604, 266–272 (2022).Article 

CAS 

PubMed 

Google Scholar 

Duan, J. et al. Giant second-order nonlinear Hall effect in twisted bilayer graphene. Phys. Rev. Lett. 129, 186801 (2022).Article 

CAS 

PubMed 

Google Scholar 

Chaudhary, S., Lewandowski, C. & Refael, G. Shift-current response as a probe of quantum geometry and electron-electron interactions in twisted bilayer graphene. Phys. Rev. Res. 4, 013164 (2022).Article 

CAS 

Google Scholar 

Kaplan, D., Holder, T. & Yan, B. Twisted photovoltaics at terahertz frequencies from momentum shift current. Phys. Rev. Res. 4, 013209 (2022).Article 

CAS 

Google Scholar 

Arora, A., Kong, J. F. & Song, J. C. W. Strain-induced large injection current in twisted bilayer graphene. Phys. Rev. B 104, L241404 (2021).Article 

CAS 

Google Scholar 

Pantaleón, P. A., Low, T. & Guinea, F. Tunable large Berry dipole in strained twisted bilayer graphene. Phys. Rev. B 103, 205403 (2021).Article 

Google Scholar 

Lu, X. et al. Superconductors, orbital magnets and correlated states in magic-angle bilayer graphene. Nature 574, 653–657 (2019).Article 

CAS 

PubMed 

Google Scholar 

Xie, Y. et al. Spectroscopic signatures of many-body correlations in magic-angle twisted bilayer graphene. Nature 572, 101–105 (2019).Article 

CAS 

PubMed 

Google Scholar 

Wong, D. et al. Cascade of electronic transitions in magic-angle twisted bilayer graphene. Nature 582, 198–202 (2020).Article 

CAS 

PubMed 

Google Scholar 

Zondiner, U. et al. Cascade of phase transitions and Dirac revivals in magic-angle graphene. Nature 582, 203–208 (2020).Article 

CAS 

PubMed 

Google Scholar 

Li, G. et al. Infrared spectroscopy for diagnosing superlattice minibands in twisted bilayer graphene near the magic angle. Nano Lett. 24, 15956–15963 (2024).Article 

CAS 

PubMed 

Google Scholar 

Xu, X., Gabor, N. M., Alden, J. S., van der Zande, A. M. & McEuen, P. L. Photo-thermoelectric effect at a graphene interface junction. Nano Lett. 10, 562–566 (2010).Article 

CAS 

PubMed 

Google Scholar 

Candussio, S. et al. Edge photocurrent driven by terahertz electric field in bilayer graphene. Phys. Rev. B 102, 45406 (2020).Article 

CAS 

Google Scholar 

Castilla, S. et al. Fast and sensitive terahertz detection using an antenna-integrated graphene pn junction. Nano Lett. 19, 2765–2773 (2019).Article 

CAS 

PubMed 

Google Scholar 

Semkin, V. A. et al. Zero-bias photodetection in 2D materials via geometric design of contacts. Nano Lett. 23, 5250–5256 (2023).Article 

CAS 

PubMed 

Google Scholar 

Sinha, S. et al. Berry curvature dipole senses topological transition in a moiré superlattice. Nat. Phys. 18, 765–770 (2022).Article 

CAS 

Google Scholar 

He, P. et al. Graphene moiré superlattices with giant quantum nonlinearity of chiral Bloch electrons. Nat. Nanotechnol. 17, 378–383 (2022).Article 

CAS 

PubMed 

Google Scholar 

Guinea, F. & Walet, N. R. Electrostatic effects, band distortions, and superconductivity in twisted graphene bilayers. Proc. Natl Acad. Sci. USA 115, 13174–13179 (2018).Article 

CAS 

PubMed 

PubMed Central 

Google Scholar 

Ma, C. et al. Moiré band topology in twisted bilayer graphene. Nano Lett. 20, 6076–6083 (2020).Article 

CAS 

PubMed 

Google Scholar 

Jiang, Y. et al. Charge order and broken rotational symmetry in magic-angle twisted bilayer graphene. Nature 573, 91–95 (2019).Article 

CAS 

PubMed 

Google Scholar 

Nuckolls, K. P. et al. Quantum textures of the many-body wavefunctions in magic-angle graphene. Nature 620, 525–532 (2023).Article 

CAS 

PubMed 

Google Scholar 

Long, M. et al. An atomistic approach for the structural and electronic properties of twisted bilayer graphene-boron nitride heterostructures. npj Comput. Mater. 8, 73 (2022).Article 

CAS 

Google Scholar 

Song, J. C. W., Shytov, A. V. & Levitov, L. S. Electron interactions and gap opening in graphene superlattices. Phys. Rev. Lett. 111, 266801 (2013).Article 

PubMed 

Google Scholar 

Jiang, J. et al. Flexo-photovoltaic effect in MoS2. Nat. Nanotechnol. 16, 894–901 (2021).Article 

CAS 

PubMed 

Google Scholar 

Zhu, M. J. et al. Edge currents shunt the insulating bulk in gapped graphene. Nat. Commun. 8, 14552 (2017).Article 

CAS 

PubMed 

PubMed Central 

Google Scholar 

Uri, A. et al. Mapping the twist-angle disorder and Landau levels in magic-angle graphene. Nature 581, 47–52 (2020).Article 

CAS 

PubMed 

Google Scholar 

Hesp, N. C. H. et al. Cryogenic nano-imaging of second-order moiré superlattices. Nat. Mater. 23, 1664–1670 (2024).Article 

CAS 

PubMed 

Google Scholar 

Choi, Y. et al. Correlation-driven topological phases in magic-angle twisted bilayer graphene. Nature 589, 536–541 (2021).Article 

CAS 

PubMed 

Google Scholar 

Kwan, Y. H. et al. Kekulé spiral order at all nonzero integer fillings in twisted bilayer graphene. Phys. Rev. X 11, 41063 (2021).CAS 

Google Scholar 

Lian, B. et al. Twisted bilayer graphene. IV. Exact insulator ground states and phase diagram. Phys. Rev. B 103, 205414 (2021).Article 

CAS 

Google Scholar 

Kim, H. et al. Imaging inter-valley coherent order in magic-angle twisted trilayer graphene. Nature 623, 942–948 (2023).Article 

CAS 

PubMed 

Google Scholar 

Song, Z.-D. & Bernevig, B. A. Magic-angle twisted bilayer graphene as a topological heavy fermion problem. Phys. Rev. Lett. 129, 47601 (2022).Article 

CAS 

Google Scholar 

Datta, A., Calderón, M. J., Camjayi, A. & Bascones, E. Heavy quasiparticles and cascades without symmetry breaking in twisted bilayer graphene. Nat. Commun. 14, 5036 (2023).Article 

CAS 

PubMed 

PubMed Central 

Google Scholar 

Tian, H. et al. Evidence for Dirac flat band superconductivity enabled by quantum geometry. Nature 614, 440–444 (2023).Article 

CAS 

PubMed 

Google Scholar 

Bandurin, D. A. et al. Resonant terahertz detection using graphene plasmons. Nat. Commun. 9, 5392 (2018).Article 

CAS 

PubMed 

PubMed Central 

Google Scholar 

Khalaf, E., Kruchkov, A. J., Tarnopolsky, G. & Vishwanath, A. Magic angle hierarchy in twisted graphene multilayers. Phys. Rev. B 100, 085109 (2019).Park, J. M. et al. Robust superconductivity in magic-angle multilayer graphene family. Nat. Mater. 21, 877–883 (2022).Article 

CAS 

PubMed 

Google Scholar 

Purdie, D. G. et al. Cleaning interfaces in layered materials heterostructures. Nat. Commun. 9, 5387 (2018).Article 

CAS 

PubMed 

PubMed Central 

Google Scholar 

Cao, Y. et al. Superlattice-induced insulating states and valley-protected orbits in twisted bilayer graphene. Phys. Rev. Lett. 117, 116804 (2016).Article 

CAS 

PubMed 

Google Scholar 

Krishna Kumar, R. Data for main text figs—terahertz photocurrent probe of quantum geometry and interactions in magic-angle twisted bilayer graphene. Zenodo https://doi.org/10.5281/zenodo.14882592 (2025).Download referencesAcknowledgementsR.B. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 847517. J.B. acknowledges support from the European Union’s Horizon Europe programme under grant agreement no. 101105218. K.N. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 713729. S.C. acknowledges funding by the Departament de Recerca i Universitats de la Generalitat de Catalunya (no. 2021 SGR 01443). E.K. acknowledges funding under the Marie Skłodowska-Curie Fellowship project SuperTera. IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (no. CEX2020-001039-S/AEI/10.13039/501100011033). P.A.P. and F.G. acknowledge funding from the European Commission, within the Graphene Flagship Core 3 via grant no. 881603 and from grant no. NMAT2D (Comunidad de Madrid, Spain), SprQuMat, from NOVMOMAT, project PID2022-142162NB-I00 funded by MICIU/AEI/10.13039/501100011033 and by FEDER, UE, as well as financial support through the (MAD2D-CM)-MRR MATERIALES AVANZADOS-IMDEA-NC. Z.Z. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 101034431. S.B.-P. acknowledges support from the ‘Presencia de la Agencia Estatal de Investigación’ within the ‘Convocatoria de tramitación anticipada, correspondente al año 2020, de las ayudas para contractos predoctorales (ref. no. PRE2020-094404) para la formación de doctores contemplada en el Subprograma Estatal de Fromación del Programa Estatal de Promoción del Talento y su Empleabilidad en I+D+i, en el marco del Plan Estatal de Investigacón Científica y Técnica de Innovación 2017–2020, cofinanciado por el Fondo Social Europeo’. E.I. and C.S. acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 881603 (Graphene Flagship) and from the European Research Council (ERC) under grant agreement no. 820254, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy—Cluster of Excellence Matter and Light for Quantum Computing (ML4Q) EXC 2004/1–390534769 and the FLAG-ERA grant PhotoTBG–471733165. H.A. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement no. 665884. K.W. and T.T. acknowledge support from JSPS KAKENHI (grant nos. 20H00354 and 23H02052) and World Premier International Research Center Initiative (WPI), MEXT, Japan. J.C.W.S. acknowledges support from the Singapore Ministry of Education under its Academic Research Fund Tier 2 grant no. MOE-T2EP50222-0011 and Tier 3 grant no. MOE-MOET32023-0003 Quantum Geometric Advantage. G.R. acknowledges support from the Simons Foundation, the ARO MURI grant no. W911NF-16-1-0361 and the Institute of Quantum Information and Matter. C.L. was supported by start-up funds from the Florida State University and the National High Magnetic Field Laboratory. The National High Magnetic Field Laboratory is supported by the National Science Foundation through NSF/DMR-2128556 and the State of Florida. P.J.-H. acknowledges support from the National Science Foundation (no. DMR-1809802), the STC Center for Integrated Quantum Materials (NSF grant no. DMR1231319), the Gordon and Betty Moore Foundation’s EPiQS Initiative through grant no. GBMF9463, the Ramon Areces Foundation and the ICFO Distinguished Visiting Professor program. This work was partially funded by CEX2019-000910-S [MCIN/AEI/10.13039/501100011033], Fundació Cellex, Fundació Mir-Puig, and Generalitat de Catalunya through CERCA. This material is based on work supported by the Air Force Office of Scientific Research under award no. FA8655-23-17047. Any opinions findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the United States Air Force. F.H.L.K. acknowledges support from the ERC TOPONANOP under grant agreement no. 726001, the Gordon and Betty Moore Foundation through grant no. GBMF12212 and the Government of Spain (nos. FIS2016-81044; PID2019-106875GB-100; and Severo Ochoa CEX2019-000910-S [MCIN/AEI/10.13039/501100011033], PCI2021-122020-2A and PDC2022-133844-100 funded by MCIN/AEI/10.13039/501100011033). This work was also supported by the European Union NextGenerationEU/PRTR (PRTR-C17.I1) and EXQIRAL 101131579, Fundació Cellex, Fundació Mir-Puig and Generalitat de Catalunya (CERCA, AGAUR, 2021 SGR 014431656). Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union Research Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. Additionally, the research leading to these results received funding from European Union’s Horizon 2020 programme under grant agreement nos. 881603 (Graphene Flagship Core 3) and 820378 (Quantum Flagship). This material is based on work supported by the Air Force Office of Scientific Research under award no. FA8655-23-1-7047. R.K.K. acknowledges funding by MCIN/AEI/10.13039/501100011033 and by the ‘European Union NextGenerationEU/PRTR’ PCI2021-122020-2A within the FLAG-ERA grant (PhotoTBG), by ICFO, RWTH Aachen and ETHZ/Department of Physics, and support from the Ramon y Cajal grant no. RYC2022-036118-I funded by MICIU/AEI/10.13039/501100011033 and by ‘ESF+’.Author informationAuthor notesThese authors contributed equally: Geng Li, Riccardo Bertini, Swati Chaudhary.Authors and AffiliationsICFO—Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), SpainRoshan Krishna Kumar, Geng Li, Riccardo Bertini, Krystian Nowakowski, Sebastian Castilla, Hitesh Agarwal, Sergi Batlle-Porro, Matteo Ceccanti, Antoine Reserbat-Plantey, Giulia Piccinini, Julien Barrier, Ekaterina Khestanova, Petr Stepanov & Frank H. L. KoppensCatalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, SpainRoshan Krishna KumarDepartment of Physics, The University of Texas, Austin, TX, USASwati ChaudharyDepartment of Physics, Massachusetts Institute of Technology, Cambridge, MA, USASwati Chaudhary, Jeong Min Park & Pablo Jarillo-HerreroIMDEA Nanociencia, Madrid, SpainZhen Zhan, Pierre A. Pantaleón & Francisco GuineaJARA-FIT and 2nd Institute of Physics, RWTH Aachen University, Aachen, GermanyEike Icking & Christoph StampferPeter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Jülich, GermanyEike Icking & Christoph StampferUniversité Côte d’Azur, CNRS, CRHEA, Sophia-Antipolis, FranceAntoine Reserbat-PlanteyResearch Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, JapanTakashi TaniguchiResearch Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, JapanKenji WatanabeDepartment of Physics and Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, CA, USAGil Refael & Cyprian LewandowskiDonostia International Physics Center, San Sebastian, SpainFrancisco GuineaDivision of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, SingaporeJustin C. W. SongDepartment of Physics and Astronomy, University of Notre Dame, Notre Dame, IN, USAPetr StepanovStavropoulos Center for Complex Quantum Matter, University of Notre Dame, Notre Dame, IN, USAPetr StepanovNational High Magnetic Field Laboratory, Tallahassee, FL, USACyprian LewandowskiDepartment of Physics, Florida State University, Tallahassee, FL, USACyprian LewandowskiICREA—Institució Catalana de Recerca i Estudis Avançats, Barcelona, SpainFrank H. L. KoppensAuthorsRoshan Krishna KumarView author publicationsYou can also search for this author inPubMed Google ScholarGeng LiView author publicationsYou can also search for this author inPubMed Google ScholarRiccardo BertiniView author publicationsYou can also search for this author inPubMed Google ScholarSwati ChaudharyView author publicationsYou can also search for this author inPubMed Google ScholarKrystian NowakowskiView author publicationsYou can also search for this author inPubMed Google ScholarJeong Min ParkView author publicationsYou can also search for this author inPubMed Google ScholarSebastian CastillaView author publicationsYou can also search for this author inPubMed Google ScholarZhen ZhanView author publicationsYou can also search for this author inPubMed Google ScholarPierre A. PantaleónView author publicationsYou can also search for this author inPubMed Google ScholarHitesh AgarwalView author publicationsYou can also search for this author inPubMed Google ScholarSergi Batlle-PorroView author publicationsYou can also search for this author inPubMed Google ScholarEike IckingView author publicationsYou can also search for this author inPubMed Google ScholarMatteo CeccantiView author publicationsYou can also search for this author inPubMed Google ScholarAntoine Reserbat-PlanteyView author publicationsYou can also search for this author inPubMed Google ScholarGiulia PiccininiView author publicationsYou can also search for this author inPubMed Google ScholarJulien BarrierView author publicationsYou can also search for this author inPubMed Google ScholarEkaterina KhestanovaView author publicationsYou can also search for this author inPubMed Google ScholarTakashi TaniguchiView author publicationsYou can also search for this author inPubMed Google ScholarKenji WatanabeView author publicationsYou can also search for this author inPubMed Google ScholarChristoph StampferView author publicationsYou can also search for this author inPubMed Google ScholarGil RefaelView author publicationsYou can also search for this author inPubMed Google ScholarFrancisco GuineaView author publicationsYou can also search for this author inPubMed Google ScholarPablo Jarillo-HerreroView author publicationsYou can also search for this author inPubMed Google ScholarJustin C. W. SongView author publicationsYou can also search for this author inPubMed Google ScholarPetr StepanovView author publicationsYou can also search for this author inPubMed Google ScholarCyprian LewandowskiView author publicationsYou can also search for this author inPubMed Google ScholarFrank H. L. KoppensView author publicationsYou can also search for this author inPubMed Google ScholarContributionsR.K.K., K.N. and F.H.L.K. conceived the experiments. R.K.K. and R.B. performed the photocurrent measurements and analysed the data with support from K.N. G.L. fabricated the D0.94, D1.12 and D1.5 devices, and performed quantum transport measurements in these devices. P.S. fabricated the D1.03 device. S.C. performed the calculations and provided theoretical support regarding the shift current. J.M.P. fabricated the D1.02 device supported by P.J.-H. S.C. performed the numerical simulations. Z.Z. and P.A.P. performed the tight-binding calculations of TBG on hBN with support from F.G. R.K.K., R.B., H.A. and A.R.-P. built the cryogenic THz photocurrent setup in which the measurements were performed. S.B.-P. and J.B. performed the supporting photocurrent measurements. M.C. provided the fabrication support and technical expertise. E.I. fabricated the bilayer graphene devices supported by C.S. G.P. fabricated the monolayer graphene devices. E.K. provided technical assistance with the THz measurements. T.T. and K.W. provided the high-quality hBN crystals. G.R. provided theoretical support. J.C.W.S., C.L. and F.H.L.K. supervised the project. R.K.K., R.B., C.L. and F.H.L.K. wrote the manuscript with input from all authors.Corresponding authorsCorrespondence to

Roshan Krishna Kumar or Frank H. L. Koppens.Ethics declarations

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Nature Materials thanks Fan Zhang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional informationPublisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Supplementary informationSupplementary InformationSupplementary Sections 1–13, Figs. 1–16 and References.Rights and permissionsSpringer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.Reprints and permissionsAbout this articleCite this articleKrishna Kumar, R., Li, G., Bertini, R. et al. Terahertz photocurrent probe of quantum geometry and interactions in magic-angle twisted bilayer graphene.

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