Plethora of many body ground states in magic angle twisted bilayer graphene

The discovery of magic angle twisted bilayer graphene (MATBG), in which two sheets of monolayer graphene are precisely stacked at a specific angle, has opened up a plethora of grand new opportunities in the field of topology, superconductivity, strange metal, and other strongly correlated effects. This review will focus on the various forms of quantum phases in MATBG revealed through quantum transport measurements. The goal is to highlight the uniqueness and current understanding of the various phases, especially how electronic interaction plays a role in them, as well as open questions in regard to the phase diagram.

[1]  Kenji Watanabe,et al.  Observation of Reentrant Correlated Insulators and Interaction-Driven Fermi-Surface Reconstructions at One Magnetic Flux Quantum per Moiré Unit Cell in Magic-Angle Twisted Bilayer Graphene. , 2022, Physical review letters.

[2]  T. Ihn,et al.  A tunable monolithic SQUID in twisted bilayer graphene , 2022, Nature Nanotechnology.

[3]  D. Efetov,et al.  Reentrant Correlated Insulators in Twisted Bilayer Graphene at 25 T (2π Flux). , 2021, Physical review letters.

[4]  Kenji Watanabe,et al.  Revealing the Thermal Properties of Superconducting Magic-Angle Twisted Bilayer Graphene. , 2021, Nano letters.

[5]  Kenji Watanabe,et al.  Isospin magnetism and spin-polarized superconductivity in Bernal bilayer graphene , 2021, Science.

[6]  K. Watanabe,et al.  Interaction-driven giant thermopower in magic-angle twisted bilayer graphene , 2021, Nature Physics.

[7]  Kenji Watanabe,et al.  Quantum critical behaviour in magic-angle twisted bilayer graphene , 2021, Nature Physics.

[8]  A. Yacoby,et al.  Fractional Chern insulators in magic-angle twisted bilayer graphene , 2021, Nature.

[9]  Kenji Watanabe,et al.  Superconductivity in rhombohedral trilayer graphene , 2021, Nature.

[10]  A. Millis,et al.  Quantum criticality in twisted transition metal dichalcogenides , 2021, Nature.

[11]  A. MacDonald,et al.  The marvels of moiré materials , 2021, Nature Reviews Materials.

[12]  T. Taniguchi,et al.  Chern insulators, van Hove singularities and topological flat bands in magic-angle twisted bilayer graphene , 2021, Nature Materials.

[13]  S. Kar,et al.  Twistronics: a turning point in 2D quantum materials , 2021, 2101.04501.

[14]  Kenji Watanabe,et al.  Competing Zero-Field Chern Insulators in Superconducting Twisted Bilayer Graphene. , 2020, Physical Review Letters.

[15]  Kenji Watanabe,et al.  Highly tunable junctions and non-local Josephson effect in magic-angle graphene tunnelling devices , 2020, Nature Nanotechnology.

[16]  T. Ihn,et al.  Gate-defined Josephson junctions in magic-angle twisted bilayer graphene , 2020, Nature Nanotechnology.

[17]  Y. Oreg,et al.  Entropic evidence for a Pomeranchuk effect in magic-angle graphene , 2020, Nature.

[18]  Kenji Watanabe,et al.  Flavour Hund’s coupling, Chern gaps and charge diffusivity in moiré graphene , 2020, Nature.

[19]  Lin He,et al.  Twistronics in graphene-based van der Waals structures , 2020, 2008.09769.

[20]  E. Andrei,et al.  Graphene bilayers with a twist , 2020, Nature Materials.

[21]  Kenji Watanabe,et al.  Symmetry-broken Chern insulators and Rashba-like Landau-level crossings in magic-angle bilayer graphene , 2020, Nature Physics.

[22]  Kenji Watanabe,et al.  Hofstadter subband ferromagnetism and symmetry-broken Chern insulators in twisted bilayer graphene , 2020, Nature Physics.

[23]  Kenji Watanabe,et al.  Untying the insulating and superconducting orders in magic-angle graphene , 2020, Nature.

[24]  P. Kim,et al.  Tunable spin-polarized correlated states in twisted double bilayer graphene , 2020, Nature.

[25]  L. Balents,et al.  Superconductivity and strong correlations in moiré flat bands , 2020 .

[26]  Kenji Watanabe,et al.  Multiple flat bands and topological Hofstadter butterfly in twisted bilayer graphene close to the second magic angle , 2020, Proceedings of the National Academy of Sciences.

[27]  Hyunmin Kim,et al.  Opportunities and Challenges in Twisted Bilayer Graphene: A Review , 2020, Nano-micro letters.

[28]  Xiaodong Xu,et al.  Electrically tunable correlated and topological states in twisted monolayer–bilayer graphene , 2020, Nature Physics.

[29]  T. Taniguchi,et al.  Tuning electron correlation in magic-angle twisted bilayer graphene using Coulomb screening , 2020, Science.

[30]  Xiaodong Xu,et al.  Superconductivity without insulating states in twisted bilayer graphene stabilized by monolayer WSe$_2$ , 2020, 2002.03003.

[31]  Y. Oreg,et al.  Cascade of phase transitions and Dirac revivals in magic-angle graphene , 2019, Nature.

[32]  Kenji Watanabe,et al.  Cascade of electronic transitions in magic-angle twisted bilayer graphene , 2019, Nature.

[33]  Kenji Watanabe,et al.  Independent superconductors and correlated insulators in twisted bilayer graphene , 2019, Nature Physics.

[34]  Xiaobo Lu,et al.  Magic-angle bilayer graphene nano-calorimeters - towards broadband, energy-resolving single photon detection. , 2019, Nano letters.

[35]  A. Vishwanath,et al.  Ground State and Hidden Symmetry of Magic-Angle Graphene at Even Integer Filling , 2019, 1911.02045.

[36]  J. Alicea,et al.  Recovery of massless Dirac fermions at charge neutrality in strongly interacting twisted bilayer graphene with disorder , 2019, Physical Review B.

[37]  J. Zhu,et al.  Intrinsic quantized anomalous Hall effect in a moiré heterostructure , 2019, Science.

[38]  R. Greene,et al.  The Strange Metal State of the Electron-Doped Cuprates , 2019, 1905.04998.

[39]  Y. Yu,et al.  Quantum anomalous Hall effect in intrinsic magnetic topological insulator MnBi2Te4 , 2019, Science.

[40]  Kenji Watanabe,et al.  Correlated states in twisted double bilayer graphene , 2019, Nature Physics.

[41]  Kenji Watanabe,et al.  Superconductors, orbital magnets and correlated states in magic-angle bilayer graphene , 2019, Nature.

[42]  T. Taniguchi,et al.  Phonon scattering dominated electron transport in twisted bilayer graphene , 2019, 1902.00763.

[43]  Kenji Watanabe,et al.  Strange Metal in Magic-Angle Graphene with near Planckian Dissipation. , 2019, Physical review letters.

[44]  M. Kastner,et al.  Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene , 2019, Science.

[45]  D. Graf,et al.  Tuning superconductivity in twisted bilayer graphene , 2018, Science.

[46]  Takashi Taniguchi,et al.  Unconventional superconductivity in magic-angle graphene superlattices , 2018, Nature.

[47]  E. Kaxiras,et al.  Correlated insulator behaviour at half-filling in magic-angle graphene superlattices , 2018, Nature.

[48]  J. Betts,et al.  Scale-invariant magnetoresistance in a cuprate superconductor , 2017, Science.

[49]  S. Larentis,et al.  Tunable moiré bands and strong correlations in small-twist-angle bilayer graphene , 2017, Proceedings of the National Academy of Sciences.

[50]  E. Kaxiras,et al.  Superlattice-Induced Insulating States and Valley-Protected Orbits in Twisted Bilayer Graphene. , 2016, Physical review letters.

[51]  R. McDonald,et al.  Scaling between magnetic field and temperature in the high-temperature superconductor BaFe2(As1−xPx)2 , 2016, Nature Physics.

[52]  L. Levitov,et al.  Topological Bloch bands in graphene superlattices , 2014, Proceedings of the National Academy of Sciences.

[53]  Q. Xue,et al.  Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator , 2013, Science.

[54]  A. P. Mackenzie,et al.  Similarity of Scattering Rates in Metals Showing T-Linear Resistivity , 2013, Science.

[55]  R. Bistritzer,et al.  Moiré butterflies in twisted bilayer graphene , 2011, 1101.2606.

[56]  P. Kim,et al.  Controlling electron-phonon interactions in graphene at ultrahigh carrier densities. , 2010, Physical review letters.

[57]  P. Vargas,et al.  Flat bands in slightly twisted bilayer graphene: Tight-binding calculations , 2010, 1012.4320.

[58]  Y. Uemura.  Condensation, excitation, pairing, and superfluid density in high-Tc superconductors: the magnetic resonance mode as a roton analogue and a possible spin-mediated pairing , 2004, cond-mat/0406301.