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REVIEW 3 major objections 5 minor 1 cited by

Heavy fermion phase diagram in magic-angle twisted trilayer graphene

T0 review · 3 major / 5 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read At a specific filling, an electric field sweeps twisted trilayer graphene from an antiferromagnetic semimetal into a heavy fermion metal, and the effective electron mass diverges at the transition.

desk verdict A solid two-device transport study showing a field-tuned AFM-semimetal to heavy-Fermi-liquid crossover in MATTG, but the headline mass-divergence/QCP claim is more suggestive than established. read the letter →

arxiv 2507.12254 v2 pith:V4GSKDGU submitted 2025-07-16 cond-mat.mes-hall cond-mat.mtrl-scicond-mat.str-el

classification cond-mat.mes-hallcond-mat.mtrl-scicond-mat.str-el
keywords magic-angletwistedtrilayergrapheneheavyfermionKondolatticequantumcriticalpointDoniachphasediagramdisplacementfieldtuningFermisurfacereconstructioneffectivemassdivergence
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper reports that applying a perpendicular displacement field to magic-angle twisted trilayer graphene at filling $\nu=3$ drives the system through a continuous quantum phase transition, from an antiferromagnetic semimetal to a paramagnetic heavy fermion metal. The tuning knob is Kondo hybridization: localized flat-band electrons act as f-moments, itinerant Dirac electrons act as c-electrons, and the displacement field shifts the balance between RKKY magnetic order and Kondo screening. The authors locate a quantum critical point near $D\approx0.5$ V/nm, where the $T^2$ resistivity coefficient $A$ diverges and the effective mass is enhanced about 33-fold to $m^* \approx 2m_0$ at $D=0.9$ V/nm, with Shubnikov-de Haas and Hall data showing a small-to-large Fermi surface reconstruction. They interpret this as a single-device, electrically tunable realization of the Doniach phase diagram usually studied in bulk heavy-fermion compounds, and a platform for exploring Kondo-lattice physics and possibly superconductivity in two dimensions.

What carries the argument

The central object is a displacement-field-tuned Doniach phase diagram at $\nu=3$ in MATTG. In Doniach's picture, a Kondo lattice has two competing scales—the RKKY exchange interaction favoring magnetic order and the Kondo screening temperature favoring a heavy Fermi liquid—and the ratio of these scales is controlled here by the perpendicular displacement field $D$. The quantitative machinery is the $T^2$ resistivity coefficient $A$, converted to effective mass via Kadowaki-Woods scaling ($A \propto m^{*2}$), whose divergence near $D\approx0.5$ V/nm is used to locate the quantum critical point; the Fermi-surface reconstruction is tracked by the Shubnikov-de Haas frequency change (old low-frequency oscillations vanish, a new 11.5 T frequency emerges) and by the Hall carrier density divergence and sign change near $D_{c2}\approx0.43$ V/nm. Supporting probes include the Curie-Weiss susceptibility for the antiferromagnetic side and the non-monotonic $R_{xy}$-$T$ curve for the heavy Fermi liquid side.

What would settle it

Measure the electronic specific-heat coefficient $\gamma(D)$ at $\nu=3$ on a fine grid of displacement fields around $D=0.5$ V/nm at millikelvin temperatures: if $\gamma$ does not track the $A$-based divergence, or if $A(D)$ with proper error bars and a denser grid fails to follow a divergent power law with scaling collapse, the quantum-critical mass-divergence claim is falsified.

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Extended reading notes

Core claim

At integer filling $\nu=3$, MATTG hosts both flat (f-electron-like) and Dirac (c-electron-like) bands, and a perpendicular displacement field $D$ controls their hybridization. The authors show that small $D$ produces a semimetallic antiferromagnet: the inverse susceptibility follows Curie-Weiss behavior with $\theta_C = -115$ K, Néel temperature $T_N \approx 15$ K, and transport shows spin-flop magnetoresistance and a giant anomalous Hall effect from skew scattering. Large $D$ produces a coherent Kondo lattice: $R_{xx}$ shows a logarithmic rise at high temperature, a coherence maximum near 54 K, and a $T^2$ Fermi-liquid regime at low temperature, with $R_{xy}$-vs-$T$ displaying the non-monotonic heavy-fermion Hall signature. Using Kadowaki-Woods scaling against a light-band reference at $\nu=5.5$, they estimate the quasiparticle mass at $D=0.9$ V/nm to be $m^* \approx 2m_0$, about 33 times heavier than the reference. As $D$ increases from 0 to 1.1 V/nm, $T_N$ moves to zero while a Kondo coherence scale $T^*$ rises, and the fitted $A$ coefficient diverges near $D\approx0.5$ V/nm; around $D_{c2}\approx0.43$ V/nm the low-frequency Shubnikov-de Haas oscillations (starting near 1.1 T) vanish and a new 11.5 T frequency appears, while the Hall carrier density diverges and changes sign, signaling a small-to-large Fermi surface reconstruction at a quantum critical point.

Load-bearing premise

The load-bearing premise is that the Kadowaki-Woods relation $A \propto m^{*2}$ holds with the same proportionality constant when comparing the heavy state at $\nu=3$ to the light one at $\nu=5.5$, so that the ratio of the fitted $A$ coefficients can be converted into the effective-mass enhancement; if that scaling fails, or if the $A(D)$ trend near $D\approx0.5$ V/nm is a smooth band effect fitted from too few points, the mass-divergence and quantum-critical-point claims lose their quantitative footing.

Editorial extensions

If this is right

  • At $D\approx0.5$ V/nm the system sits at a zero-temperature quantum critical point, so cooling further should sharpen the divergence of the $A$ coefficient and the effective mass rather than saturating it.
  • The disappearance of low-frequency Shubnikov-de Haas oscillations (starting near 1.1 T) and the emergence of a new 11.5 T frequency on the high-$D$ side mean the Kondo singlets add the localized flat-band electrons to the Fermi volume, a defining heavy-fermion signature.
  • The same gate-tunable quantum critical point offers a clean two-dimensional analog of pressure-tuned heavy-fermion compounds, with continuous access to the critical regime in a single device.
  • The superconductivity observed at $\nu=2\pm\delta$ in the same device at 0.25 K sits adjacent to the heavy-fermion regime, suggesting that the same Kondo and quantum-critical fluctuations may provide the pairing glue.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: the $A(D)$ divergence is currently supported by a small number of fitted points without error bars; a dense $D$-sweep at millikelvin temperatures with a scaling collapse test would determine whether the singularity is a true power-law divergence or a smooth Lifshitz-like crossover.
  • Editorial inference: if the mass enhancement is genuinely Kondo in origin, the heavy quasiparticles near $D\approx0.5$ V/nm should also produce strongly enhanced thermopower and specific-heat coefficient $\gamma$, giving independent checks that do not rely on Kadowaki-Woods scaling.
  • Editorial inference: the displacement-field axis that tunes the heavy-fermion quantum critical point could be used to drive the nearby superconductivity at $\nu=2\pm\delta$ across its own quantum critical regime, enabling a systematic comparison with pressure-tuned heavy-fermion superconductors.
  • Editorial inference: measuring the field-angle dependence of the heavy-fermion Fermi surface could reveal whether the composite fermions carry orbital or spin character, distinguishing Kondo-singlet formation from a Lifshitz transition of purely band-hybridization origin.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The manuscript reports transport measurements on magic-angle twisted trilayer graphene (MATTG) at filling factor ν=3 as a function of displacement field D and temperature. It claims an electrically tunable heavy-fermion phase diagram: an antiferromagnetic semimetal at low D, a paramagnetic heavy Fermi liquid at high D, and a continuous quantum phase transition at D≈0.5 V/nm evidenced by an apparent divergence of the T² resistivity coefficient A and of the effective mass, accompanied by Fermi surface reconstruction. The endpoint phases are supported by representative Rxx(T) curves, Kondo log-T upturns, coherence peaks, T² Fermi-liquid behavior, anomalous Hall effect, Curie-Weiss susceptibility, Landau fans, and consistency across two devices. However, the central quantitative claims of a quantum critical point and effective-mass divergence rest on A(D) fits with no reported error bars, no power-law form or scaling collapse, and on an unvalidated conversion from A to m*.

Significance. If the central claims hold, the paper would establish a gate-tunable two-dimensional Doniach phase diagram and a heavy-fermion quantum critical point in a moiré system, which would be of broad interest to the correlated-electron and moiré communities. The strengths are the two-device reproducibility, the multiple complementary transport signatures used to identify the endpoint phases, and the direct observation of Fermi surface expansion via SdH frequency shifts. The limitation is that the quantum-critical and mass-divergence part of the headline claim is quantitatively underdetermined by the presented analysis, so the significance of the paper as a demonstration of a continuous QCP is not yet established.

major comments (3)
  1. [Fig. 3(b) and the section 'The standard Rxx-T curve and dramatic enhancement of effective mass'] The central claim of a continuous quantum phase transition with effective-mass divergence rests on the statement in Fig. 3(b) that 'the fitted coefficients A for discrete displacement fields D exhibit a divergent behavior upon approaching D≈0.5 V/nm.' No error bars, number of points, fitting form, or statistical measure are provided, and no scaling collapse of the Rxx-T curves is shown. With only a small number of discrete points, a monotonic increase cannot be distinguished from a genuine divergence. In addition, the quoted critical field D≈0.5 V/nm is inconsistent with Dc2=0.43 V/nm quoted in the Fig. 4 discussion. The authors should report A(D) with uncertainties and fit a power-law form with an exponent and fitting range, or provide a scaling collapse, before the QCP and mass-divergence claims can be evaluated.
  2. [The standard Rxx-T curve and dramatic enhancement of effective mass] The mass estimate m*≈2m0 rests on the assumption that the same A-to-m* proportionality holds at ν=3 and ν=5.5 and at all D. The text states that 'A is linearly proportional to the quasiparticle effective mass m* according to Kadowaki-Woods scaling,' but Kadowaki-Woods scaling is conventionally A ∝ (m*)², and neither proportionality is shown to hold with a D-independent constant in MATTG. The arithmetic is also inconsistent: A(0.9 V/nm)=0.5 vs 0.02 at ν=5.5 gives a ratio of 25, which would imply a mass ratio of 5 (if A ∝ m*²) or 25 (if A ∝ m*), not the stated 33-fold enhancement yielding m*≈2m0. The authors should calibrate the conversion with SdH masses at several D values, or present the mass enhancement only as a qualitative estimate.
  3. [Fig. 4 and the discussion of fermiology evolution] The paper's own tight-binding calculation (Fig. 1(b,c)) and the discussion of Fig. 4(b) show that the displacement field strongly reshapes the band structure by hybridizing flat and Dirac bands and shifting Dirac bands energetically. The observed resistance peak, the Hall carrier density divergence and sign reversal near Dc2=0.43 V/nm, and the disappearance and re-emergence of SdH frequencies are therefore also naturally explained by a single-particle Lifshitz or hybridization transition. The manuscript does not provide a quantitative test distinguishing a Kondo-driven QCP from this band-structure scenario, for example a divergent quasiparticle mass extracted directly from quantum oscillations where they exist, or a scaling collapse in D and T. As stated, the evidence is consistent with, but does not uniquely establish, the heavy-fermion QCP interpretation.
minor comments (5)
  1. [Abstract and introduction] The abstract says 'continuous quantum phase transition' while the introduction says 'continuous crossover from a heavy Fermi liquid to an antiferromagnetic semimetal'; these are not equivalent statements and should be harmonized, especially since no zero-temperature scaling analysis is presented.
  2. [Fig. 3 and main text] The notation 'A 0.5' in the text should read 'A ≈ 0.5 Ω/K²', and units should be given consistently for all A coefficients.
  3. [Fig. 3(a) caption] The definitions of T* and T_HFL are only given in the caption ('determined from dRxx/dT' and 'identified when the Rxx-T curve deviates from the Fermi-liquid T² dependence'); explicit numerical criteria and representative fitting ranges should be stated in the text or Methods.
  4. [End Matter] The End Matter introduces substantial additional claims about the isospin Pomeranchuk effect, superconductivity, Pauli-limit violation, and a Berezinskii-Kosterlitz-Thouless transition that are not mentioned in the abstract or conclusion and are not analyzed with the same depth as the main claims; the authors should either integrate these results into the main narrative or clearly present them as preliminary observations.
  5. [Fig. 4 discussion] The sentence 'Near Dc2 = 0.43 V/nm, however, the fermiology remains unclear due to the absence of well-defined SdH oscillations' directly undermines the use of SdH-derived masses as an anchor for the mass divergence, and this limitation should be acknowledged in the main text where the divergence is claimed.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the heavy-fermion phase diagram is extracted from transport data via standard phenomenological analysis, not by defining the predicted quantities into existence.

full rationale

The paper's central claims rest on measured transport quantities: the fitted T^2 coefficient A(D), SdH-derived effective masses, Hall densities, and characteristic temperatures extracted from Rxx(T). These are empirical descriptors of the data, not parameters fitted to one subset and then 'predicted' for a closely related quantity. The conversion of A into m* uses the external Kadowaki-Woods scaling hypothesis calibrated at nu=5.5 and applied at nu=3; this is an assumption external to the data, not a circular reduction. The phase boundaries (TN, T*, THFL) are obtained from the same Rxx-T curves used to draw the phase diagram, but that is standard phenomenological phase-diagram construction, not a self-definitional loop: the boundaries are not defined as the output of a model whose input is the same boundary. The paper explicitly acknowledges the most fragile region, stating that near Dc2=0.43 V/nm 'the fermiology remains unclear due to the absence of well-defined SdH oscillations,' which is a stated limitation rather than a hidden circular step. Self-citations (e.g., the tight-binding calculations in the supplemental material) are supporting computational methods and are not used as a load-bearing uniqueness theorem or as the sole justification for the central claim. The heavy-fermion interpretation is model-based but not circular: it applies a known theoretical framework (Kondo lattice/Doniach picture) to independently measured transport signatures. No step in the derivation chain equates the target result with an input by construction, and no fitted parameter is renamed as a prediction. The quantitative support for the QCP is weaker than the abstract implies, but that is a statistical/robustness concern, not a circularity concern.

Assumptions & free parameters 5 free parameters · 5 assumptions · 0 invented entities

The central claims are built on fitted transport parameters and interpretive assumptions rather than on new postulates. The main inferential load is carried by the Kadowaki-Woods conversion and by the assignment of transport signatures to Kondo physics; no new particles or fields are introduced. If the Kadowaki-Woods assumption or the skew-scattering assignment fails, the heavy fermion and QCP claims weaken accordingly.

free parameters (5)
  • A coefficient A(D) = ~0.02 Ω/K² at ν=5.5; up to ~0.5 Ω/K² at ν=3, D=0.9 V/nm
    Quadratic resistivity coefficient extracted from Rxx(T) fits; the D-dependence of these fits is the main evidence for mass enhancement and for the QCP.
  • Effective mass m* = ~0.005 m0 (Dirac low-field); 0.06 m0 at ν=5.5; ~2 m0 at ν=3, D=0.9 V/nm via Kadowaki-Woods
    Extracted from SdH temperature damping and converted from A coefficients using Kadowaki-Woods scaling; used to claim heavy fermion behavior.
  • Curie-Weiss temperature θ_C = -115 K
    Fitted from the linear part of 1/χ versus T at D=0, used to argue antiferromagnetic RKKY interactions dominate at low D.
  • Characteristic temperatures T_N, T*, T_HFL = T_N≈15 K at D=0; T* rises beyond D≈0.4 V/nm; T_HFL from T² deviation
    Read from extrema and derivatives of Rxx(T); these values define the phase boundaries in the Doniach diagram.
  • Critical displacement fields Dc1, Dc2 = Dc1=0.31 V/nm, Dc2=0.43 V/nm
    Extrapolated from magneto-interminivalley oscillation (MIO) convergence and Hall carrier density divergence; used to place the Lifshitz transition and QCP.
assumptions (5)
  • domain assumption Kadowaki-Woods scaling A ∝ (m*)² holds with the same proportionality constant at ν=5.5 and ν=3
    This is the link that converts the A coefficient ratio into m*≈2m0; no independent specific-heat measurement is provided to verify the ratio.
  • domain assumption The logarithmic resistance rise and the resistance maximum at ~54 K mark single-ion Kondo scattering and coherence onset, respectively
    Alternative sources of a resistance maximum, such as phonon scattering or band structure effects, are not quantitatively excluded.
  • domain assumption The anomalous Hall effect at D=0 originates from extrinsic skew scattering by localized moments, allowing χ≈∂Rxy/∂H to be treated as magnetic susceptibility
    The linear σ_AHE versus σ_xx relation is used to justify this assignment, but no direct magnetization measurement is presented.
  • domain assumption The low-D phase at ν=3 is an antiferromagnetic semimetal with static local moments
    Evidence is purely transport-based (spin-flop MR, AHE, Curie-Weiss 1/χ); no thermodynamic or microscopic magnetic probe is shown.
  • ad hoc to paper The displacement field acts primarily as a Kondo coupling knob, not merely as a single-particle band-structure tuning parameter
    The paper's central narrative depends on the Kondo hybridization interpretation, but the accompanying tight-binding bands show D also changes hybridization and Dirac band energy, which can enhance mass without Kondo physics.

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Cite this review

Pith. "Pith review of Heavy fermion phase diagram in magic-angle twisted trilayer graphene." pith.science (2026). https://pith.science/paper/V4GSKDGU

@misc{pith2026250712254,
  author       = {Pith},
  title        = {Pith review of: Heavy fermion phase diagram in magic-angle twisted trilayer graphene},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/V4GSKDGU}},
  note         = {Machine review of arXiv:2507.12254}
}
read the original abstract

The interplay between localized magnetic moments and itinerant electrons gives rise to exotic quantum states in condensed matter systems. Here, we demonstrate an electrically tunable heavy fermion phase diagram in magic-angle twisted trilayer graphene, achieved by controlling the Kondo hybridization between localized flat-band electrons and itinerant Dirac electrons via a displacement field. Our results reveal a continuous quantum phase transition from an antiferromagnetic semimetal to a paramagnetic heavy fermion metal. At quantum critical point, we observe effective mass divergence and Fermi surface reconstruction. This highly tunable platform offers unprecedented control over heavy fermion physics, establishing moire heterostructures as a versatile arena for exploring correlated quantum phases-including potential unconventional superconductivity-in two-dimensional limit.

Figures

Figures reproduced from arXiv: 2507.12254 by the authors.

Figure 1
Figure 1. FIG. 1. (a) Schematic of the dual-gated MATTG device. (b), [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. (h) (TN ≈ 15 K), identified from the deviation from linearity in 1/χ, aligns well with the TN = 14.2 K deter￾mined from the minimum in the derivative dRxx/dT −T at same D = 0 V nm−1 (Fig. S12). The yielded |θC | much larger than TN indicates the competition between the RKKY interaction and the Kondo effect, which fre￾quently occurs in heavy fermion systems [37, 38]. These features provide strong evidence for the eme… view at source ↗
Figure 3
Figure 3. (b). In the low-displacement-field AFM semimetal phase, static Kondo screening is absent. This means the ground state is not a Kondo singlet, and fully developed Kondo resonances do not form. Consequently, only itin￾erant Dirac electrons contribute to the Fermi volume, re￾sulting in a small Fermi surface. In contrast, in the high￾displacement-field heavy fermion liquid phase, the Kondo singlet ground state gives ris… view at source ↗
Figures from the paper (4 more)
Figure 5
Figure 5. Figure 5: FIG. 5. Phase diagram for heavy fermions in MATTG at [PITH_FULL_IMAGE:figures/full_fig_p005_5.png]
Figure 4
Figure 4. Figure 4: FIG. 4. (a) Hall carrier density [PITH_FULL_IMAGE:figures/full_fig_p005_4.png]
Figure 6
Figure 6. Figure 6: FIG. 6. Longitudinal resistance [PITH_FULL_IMAGE:figures/full_fig_p009_6.png]
Figure 7
Figure 7. Figure 7: FIG. 7. (a) [PITH_FULL_IMAGE:figures/full_fig_p009_7.png]

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Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Displacement-Field-Driven Semimetal-Superconductor Transition in Magic-Angle Twisted Trilayer Graphene

    cond-mat.str-el 2026-06 unverdicted novelty 5.0 of 10

    Slave-particle theory shows displacement field drives semimetal-superconductor transition in MATTG at ν=±2 via self-doping of the TBG sector.

Reference graph

Works this paper leans on

72 extracted references · 56 canonical work pages · cited by 1 Pith paper

  1. [1]

    J. G. Checkelsky, B. A. Bernevig, P. Coleman, Q. M. Si, and S. Paschen, Flat bands, strange metals and the Kondo effect, Nat. Rev. Mater.9, 509 (2024)

  2. [2]

    Y. Cao, V. Fatemi, S. Fang, K. Watanabe, T. Taniguchi, E. Kaxiras, and P. Jarillo-Herrero, Unconventional super- conductivity in magic-angle graphene superlattices, Na- ture556, 43 (2018)

  3. [3]

    X. Lu, P. Stepanov, W. Yang, M. Xie, M. A. Aamir, I. Das, C. Urgell, K. Watanabe, T. Taniguchi, G. Zhang, A. Bachtold, A. H. MacDonald, and D. K. Efetov, Su- perconductors, orbital magnets and correlated states in magic-angle bilayer graphene, Nature574, 653 (2019)

  4. [4]

    Y. Cao, V. Fatemi, A. Demir, S. Fang, S. L. Tomarken, J. Y. Luo, J. D. Sanchez-Yamagishi, K. Watanabe, T. Taniguchi, E. Kaxiras, R. C. Ashoori, and P. Jarillo- Herrero, Correlated insulator behaviour at half-filling in magic-angle graphene superlattices, Nature556, 80 (2018)

  5. [5]

    Chou and S

    Y.-Z. Chou and S. Das Sarma, Kondo Lattice Model in Magic-Angle Twisted Bilayer Graphene, Phys. Rev. Lett. 131, 026501 (2023)

  6. [6]

    Kumar, N

    A. Kumar, N. C. Hu, A. H. MacDonald, and A. C. Pot- ter, Gate-tunable heavy fermion quantum criticality in a moir´ e Kondo lattice, Phys. Rev. B106, 041116 (2022)

  7. [7]

    Guerci, J

    D. Guerci, J. Wang, J. Zang, J. Cano, J. H. Pixley, and A. Millis, Chiral Kondo lattice in doped MoTe 2/WSe2 bilayers, Sci. Adv.9, eade7701 (2023)

  8. [8]

    Ghosh, S

    A. Ghosh, S. Chakraborty, R. Dutta, A. Agarwala, K. Watanabe, T. Taniguchi, S. Banerjee, N. Trivedi, S. Muk- erjee, and A. Das, Thermopower probes of emergent local moments in magic-angle twisted bilayer graphene, Nat. Phys.21, 732 (2025)

Show all 72 references
  1. [9]

    R. L. Merino, D. C˘ alug˘ aru, H. Hu, J. D ´ ıez-M´ erida, A. D ´ ıez-Carl´ on, T. Taniguchi, K. Watanabe, P. Seifert, B. A. Bernevig, and D. K. Efetov, Interplay between light and heavy electron bands in magic-angle twisted bilayer graphene, Nat. Phys.21, 1078 (2025)

  2. [10]

    A. T. Pierce, Y. Xie, J. M. Park, Z. Cai, K. Watanabe, T. Taniguchi, P. Jarillo-Herrero, and A. Yacoby, Tunable interplay between light and heavy electrons in twisted trilayer graphene, Nat. Phys.21, 1237 (2025)

  3. [11]

    Z. D. Song and B. A. Bernevig, Magic-Angle Twisted Bi- layer Graphene as a Topological Heavy Fermion Problem, Phys. Rev. Lett.129, 047601 (2022)

  4. [12]

    Zhou, Y.-J

    G.-D. Zhou, Y.-J. Wang, N. Tong, and Z.-D. Song, Kondo phase in twisted bilayer graphene, Phys. Rev. B 109, 045419 (2024)

  5. [13]

    H. Hu, B. A. Bernevig, and A. M. Tsvelik, Kondo Lat- tice Model of Magic-Angle Twisted-Bilayer Graphene: Hund’s Rule, Local-Moment Fluctuations, and Low- Energy Effective Theory, Phys. Rev. Lett.131, 026502 (2023)

  6. [14]

    L. L. H. Lau and P. Coleman, Topological Mixed Valence Model for Twisted Bilayer Graphene, Phys. Rev. X15, 041015 (2025)

  7. [15]

    J. M. Park, Y. Cao, K. Watanabe, T. Taniguchi, and P. Jarillo-Herrero, Tunable strongly coupled superconduc- tivity in magic-angle twisted trilayer graphene, Nature 590, 249 (2021)

  8. [16]

    J.-X. Lin, P. Siriviboon, H. D. Scammell, S. Liu, D. Rhodes, K. Watanabe, T. Taniguchi, J. Hone, M. S. Scheurer, and J. I. A. Li, Zero-field superconducting diode effect in small-twist-angle trilayer graphene, Nat. Phys.18, 1221 (2022)

  9. [17]

    Z. Hao, A. M. Zimmerman, P. Ledwith, E. Khalaf, D. H. Najafabadi, K. Watanabe, T. Taniguchi, A. Vishwanath, and P. Kim, Electric field-tunable superconductivity in alternating-twist magic-angle trilayer graphene, Science 371, 1133 (2021)

  10. [18]

    W. Zhao, B. Shen, Z. Tao, Z. Han, K. Kang, K. Watan- abe, T. Taniguchi, K. F. Mak, and J. Shan, Gate-tunable heavy fermions in a moir´ e Kondo lattice, Nature616, 61 (2023)

  11. [19]

    W. J. Zhao, B. W. Shen, Z. Tao, S. Kim, P. Kn¨ uppel, Z. D. Han, Y. C. Zhang, K. Watanabe, T. Taniguchi, D. Chowdhury, J. Shan, and K. F. Mak, Emergence of ferromagnetism at the onset of moir´ e Kondo breakdown, Nat. Phys.20, 1772 (2024)

  12. [20]

    Ramires and J

    A. Ramires and J. L. Lado, Emulating Heavy Fermions in Twisted Trilayer Graphene, Phys. Rev. Lett.127, 026401 (2021)

  13. [21]

    J. B. Yu, M. Xie, B. A. Bernevig, and S. Das Sarma, Magic-angle twisted symmetric trilayer graphene as a topological heavy-fermion problem, Phys. Rev. B108, 035129 (2023)

  14. [22]

    See Supplemental Material at http://link.aps.org/supplemental/10.1103/zzks-vkl2 for details on the device fabrications, the band struc- ture calculations, and additional data analysis, which includes Refs. [62–72]

  15. [23]

    K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, M. I. Katsnelson, I. V. Grigorieva, S. V. Dubonos, and A. A. Firsov, Two-dimensional gas of massless Dirac fermions in graphene, Nature438, 197 (2005)

  16. [24]

    Zhang, Y

    Y. Zhang, Y. W. Tan, H. L. Stormer, and P. Kim, Ex- perimental observation of the quantum Hall effect and 7 Berry’s phase in graphene, Nature438, 201 (2005)

  17. [25]

    C. Shen, P. J. Ledwith, K. Watanabe, T. Taniguchi, E. Khalaf, A. Vishwanath, and D. K. Efetov, Dirac spec- troscopy of strongly correlated phases in twisted trilayer graphene, Nat. Mater.22, 316 (2023)

  18. [26]

    X. X. Liu, N. J. Zhang, K. Watanabe, T. Taniguchi, and J. I. A. Li, Isospin order in superconducting magic-angle twisted trilayer graphene, Nat. Phys.18, 522 (2022)

  19. [27]

    J.-H. Chen, L. Li, W. G. Cullen, E. D. Williams, and M. S. Fuhrer, Tunable Kondo effect in graphene with defects, Nat. Phys.7, 535 (2011)

  20. [28]

    A. C. Jacko, J. O. Fjærestad, and B. J. Powell, A uni- fied explanation of the Kadowaki–Woods ratio in strongly correlated metals, Nat. Phys.5, 422 (2009)

  21. [29]

    Kadowaki and S

    K. Kadowaki and S. B. Woods, Universal Relationship of the Resistivity and Specific-Heat in Heavy-Fermion Com- pounds, Solid State Commun.58, 507 (1986)

  22. [30]

    Paschen, T

    S. Paschen, T. Luhmann, S. Wirth, O. Trovarelli, C. Geibel, and F. Steglich, Anomalous hall effect in YbRh2Si2, Physica B359, 44 (2005)

  23. [31]

    Fert and P

    A. Fert and P. M. Levy, Theory of the Hall effect in heavy-fermion compounds, Phys. Rev. B36, 1907 (1987)

  24. [32]

    Y. Luo, F. Ronning, N. Wakeham, X. Lu, T. Park, Z. A. Xu, and J. D. Thompson, Pressure-tuned quan- tum criticality in the antiferromagnetic Kondo semimetal CeNi2 –δAs2, Proc. Natl. Acad. Sci. U.S.A.112, 13520 (2015)

  25. [33]

    Torres, J

    K. Torres, J. Y. Park, V. A. Posey, M. E. Ziebel, C. E. Casaday, K. J. Anderton, D. Cui, B. Tang, T. Taniguchi, K. Watanabe, A. N. Pasupathy, X. Roy, and P. Kim, Glassy relaxation dynamics in the two-dimensional heavy fermion antiferromagnet CeSiI, Nano Lett.25, 6848 (2025)

  26. [34]

    V. A. Posey, S. Turkel, M. Rezaee, A. Devarakonda, A. K. Kundu, C. S. Ong, M. Thinel, D. G. Chica, R. A. Vitalone, R. Jing, S. Xu, D. R. Needell, E. Meirzadeh, M. L. Feuer, A. Jindal, X. Cui, T. Valla, P. Thunstrom, T. Yilmaz, E. Vescovo, D. Graf, X. Zhu, A. Scheie, A. F. May,...

  27. [35]

    Y. Guo, J. Pack, J. Swann, L. Holtzman, M. Cothrine, K. Watanabe, T. Taniguchi, D. G. Mandrus, K. Barmak, J. Hone, A. J. Millis, A. Pasupathy, and C. R. Dean, Superconductivity in 5.0 ◦ twisted bilayer WSe 2, Nature 637, 839 (2025)

  28. [36]

    Anderson, F.-R

    E. Anderson, F.-R. Fan, J. Cai, W. Holtzmann, T. Taniguchi, K. Watanabe, D. Xiao, W. Yao, and X. Xu, Programming correlated magnetic states with gate- controlled moir´ e geometry, Science381, 325 (2023)

  29. [37]

    Trovarelli, C

    O. Trovarelli, C. Geibel, S. Mederle, C. Langhammer, F. M. Grosche, P. Gegenwart, M. Lang, G. Sparn, and F. Steglich, YbRh2Si2: pronounced non-Fermi-liquid effects above a low-lying magnetic phase transition, Phys. Rev. Lett.85, 626 (2000)

  30. [38]

    Gegenwart, J

    P. Gegenwart, J. Custers, C. Geibel, K. Neu- maier, T. Tayama, K. Tenya, O. Trovarelli, and F. Steglich, Magnetic-field induced quantum critical point in YbRh2Si2, Phys. Rev. Lett.89, 056402 (2002)

  31. [39]

    Polshyn, J

    H. Polshyn, J. Zhu, M. A. Kumar, Y. Zhang, F. Yang, C. L. Tschirhart, M. Serlin, K. Watanabe, T. Taniguchi, A. H. MacDonald, and A. F. Young, Electrical switching of magnetic order in an orbital Chern insulator, Nature 588, 66 (2020)

  32. [40]

    D. Xiao, W. Yao, and Q. Niu, Valley-contrasting physics in graphene: magnetic moment and topological trans- port, Phys. Rev. Lett.99, 236809 (2007)

  33. [41]

    S. Nair, S. Wirth, S. Friedemann, F. Steglich, Q. Si, and A. J. Schofield, Hall effect in heavy fermion metals, Adv. Phys.61, 583 (2012)

  34. [42]

    Si and F

    Q. Si and F. Steglich, Heavy fermions and quantum phase transitions, Science329, 1161 (2010)

  35. [43]

    J. Xiao, A. Inbar, J. Birkbeck, N. Gershon, Y. Zamir, Y. Vituri, T. Taniguchi, K. Watanabe, E. Berg, and S. Ilani, Imaging the flat bands of magic-angle graphene reshaped by interactions, Nature653, 68 (2026)

  36. [44]

    Shishido, R

    H. Shishido, R. Settai, H. Harima, and Y. ¯Onuki, A dras- tic change of the Fermi surface at a critical pressure in CeRhIn5: dHvA study under pressure, J. Phys. Soc. Jpn. 74, 1103 (2005)

  37. [45]

    I. Y. Phinney, A. Zimmerman, Z. Hao, P. J. Ledwith, T. Taniguchi, K. Watanabe, A. Vishwanath, and P. Kim, Modulation of superconductivity across a Lifshitz tran- sition in alternating-angle twisted quadrilayer graphene, Phys. Rev. Lett.136, 086501 (2026)

  38. [46]

    Tomic, P

    P. Tomic, P. Rickhaus, A. Garcia-Ruiz, G. Zheng, E. Por- toles, V. Fal’ko, K. Watanabe, T. Taniguchi, K. Ensslin, T. Ihn, and F. K. de Vries, Scattering between Mini- valleys in Twisted Double Bilayer Graphene, Phys. Rev. Lett.128, 057702 (2022)

  39. [47]

    H. Zhou, L. Holleis, Y. Saito, L. Cohen, W. Huynh, C. L. Patterson, F. Yang, T. Taniguchi, K. Watanabe, and A. F. Young, Isospin magnetism and spin-polarized su- perconductivity in Bernal bilayer graphene, Science375, 774 (2022)

  40. [48]

    H. Zhou, T. Xie, A. Ghazaryan, T. Holder, J. R. Ehrets, E. M. Spanton, T. Taniguchi, K. Watanabe, E. Berg, M. Serbyn, and A. F. Young, Half- and quarter-metals in rhombohedral trilayer graphene, Nature598, 429 (2021)

  41. [49]

    I. Y. Phinney, D. A. Bandurin, C. Collignon, I. A. Dmitriev, T. Taniguchi, K. Watanabe, and P. Jarillo- Herrero, Strong Interminivalley Scattering in Twisted Bi- layer Graphene Revealed by High-Temperature Magneto- Oscillations, Phys. Rev. Lett.127, 056802 (2021)

  42. [50]

    S. Carr, C. Li, Z. Zhu, E. Kaxiras, S. Sachdev, and A. Kruchkov, Ultraheavy and Ultrarelativistic Dirac Quasi- particles in Sandwiched Graphenes, Nano Lett.20, 3030 (2020)

  43. [51]

    Khalaf, A

    E. Khalaf, A. J. Kruchkov, G. Tarnopolsky, and A. Vish- wanath, Magic angle hierarchy in twisted graphene mul- tilayers, Phys. Rev. B100, 085109 (2019)

  44. [52]

    Y. Cao, J. M. Park, K. Watanabe, T. Taniguchi, and P. Jarillo-Herrero, Pauli-limit violation and re-entrant superconductivity in moire graphene, Nature595, 526 (2021)

  45. [53]

    S. Ran, C. Eckberg, Q. P. Ding, Y. Furukawa, T. Metz, S. R. Saha, I. L. Liu, M. Zic, H. Kim, J. Paglione, and N. P. Butch, Nearly ferromagnetic spin-triplet supercon- ductivity, Science365, 684 (2019)

  46. [54]

    J. M. Park, Y. Cao, K. Watanabe, T. Taniguchi, and P. Jarillo-Herrero, Flavour Hund’s coupling, Chern gaps and charge diffusivity in moire graphene, Nature592, 43 (2021)

  47. [55]

    D. Wong, K. P. Nuckolls, M. Oh, B. Lian, Y. Xie, S. Jeon, K. Watanabe, T. Taniguchi, B. A. Bernevig, and A. Yazdani, Cascade of electronic transitions in magic- angle twisted bilayer graphene, Nature582, 198 (2020). 8

  48. [56]

    Zondiner, A

    U. Zondiner, A. Rozen, D. Rodan-Legrain, Y. Cao, R. Queiroz, T. Taniguchi, K. Watanabe, Y. Oreg, F. von Oppen, A. Stern, E. Berg, P. Jarillo-Herrero, and S. Ilani, Cascade of phase transitions and Dirac revivals in magic- angle graphene, Nature582, 203 (2020)

  49. [57]

    Rozen, J

    A. Rozen, J. M. Park, U. Zondiner, Y. Cao, D. Rodan- Legrain, T. Taniguchi, K. Watanabe, Y. Oreg, A. Stern, E. Berg, P. Jarillo-Herrero, and S. Ilani, Entropic evi- dence for a Pomeranchuk effect in magic-angle graphene, Nature592, 214 (2021)

  50. [58]

    Saito, F

    Y. Saito, F. Yang, J. Ge, X. Liu, T. Taniguchi, K. Watan- abe, J. I. A. Li, E. Berg, and A. F. Young, Isospin Pomer- anchuk effect in twisted bilayer graphene, Nature592, 220 (2021)

  51. [59]

    X. Han, Y. Zou, Q. Liu, Z. Wang, R. Niu, Z. Qu, Z. Li, C. Han, K. Watanabe, T. Taniguchi, B. Dong, Z. Song, J. Mao, Z. Han, Z. G. Cheng, Z. Gan, and J. Lu, Suppression of symmetry-breaking correlated insulators in a rhombohedral trilayer graphene superlattice, Nat. Commun.15, ...

  52. [60]

    M. J. Zhang, X. Zhao, K. Watanabe, T. Taniguchi, Z. Zhu, F. C. Wu, Y. Q. Li, and Y. Xu, Tuning Quan- tum Phase Transitions at Half Filling in 3L-MoTe2/WSe2 Moire Superlattices, Phys. Rev. X12, 041015 (2022)

  53. [61]

    Gegenwart, Q

    P. Gegenwart, Q. Si, and F. Steglich, Quantum criticality in heavy-fermion metals, Nat. Phys.4, 186 (2008)

  54. [62]

    D ´ ıez-M´ erida, I

    J. D ´ ıez-M´ erida, I. Das, G. Di Battista, A. D ´ ıez-Carl´ on, M. Lee, L. Zeng, K. Watanabe, T. Taniguchi, E. Olsson, and D. K. Efetov, High-yield fabrication of bubble-free magic-angle twisted bilayer graphene devices with high twist-angle homogeneity, Newton1, 100007 (2025)

  55. [63]

    Z. Wu, Z. Zhan, and S. Yuan, Lattice relaxation, mirror symmetry and magnetic field effects on ultraflat bands in twisted trilayer graphene, Sci. China-Phys. Mech. As- tron.64, 267811 (2021)

  56. [64]

    Plimpton, Fast Parallel Algorithms for Short-Range Molecular Dynamics, J

    S. Plimpton, Fast Parallel Algorithms for Short-Range Molecular Dynamics, J. Comput. Phys.117, 1 (1995)

  57. [65]

    J. H. Los and A. Fasolino, Intrinsic long-range bond- order potential for carbon: Performance in Monte Carlo simulations of graphitization, Phys. Rev. B68, 024107 (2003)

  58. [66]

    A. N. Kolmogorov and V. H. Crespi, Registry-dependent interlayer potential for graphitic systems, Phys. Rev. B 71, 235415 (2005)

  59. [67]

    Jobst, D

    J. Jobst, D. Waldmann, I. V. Gornyi, A. D. Mirlin, and H. B. Weber, Electron-Electron Interaction in the Mag- netoresistance of Graphene, Phys. Rev. Lett.108, 106601 (2012)

  60. [68]

    A. S. Kumar, K. Premasiri, M. Gao, U. R. Kumar, R. Sankar, F.-C. Chou, and X. P. A. Gao, Electron-electron interactions in the two-dimensional semiconductor InSe, Phys. Rev. B102, 121301 (2020)

  61. [69]

    B. L. Altshuler, A. G. Aronov, and P. A. Lee, Interaction Effects in Disordered Fermi Systems in Two Dimensions, Phys. Rev. Lett.44, 1288 (1980)

  62. [70]

    Petrovic, P

    C. Petrovic, P. G. Pagliuso, M. F. Hundley, R. Movshovich, J. L. Sarrao, J. D. Thompson, Z. Fisk, and P. Monthoux, Heavy-fermion superconductivity in CeCoIn5 at 2.3 K, J. Phys.: Condens. Matter13, L337 (2001)

  63. [71]

    Kirchner, S

    S. Kirchner, S. Paschen, Q. Chen, S. Wirth, D. Feng, J. D. Thompson, and Q. Si, Colloquium: Heavy-electron quantum criticality and single-particle spectroscopy, Rev. Mod. Phys.92, 011002 (2020)

  64. [72]

    J. K. Dong, H. Zhang, X. Qiu, B. Y. Pan, Y. F. Dai, T. Y. Guan, S. Y. Zhou, D. Gnida, D. Kaczorowski, and S. Y. Li, Field-Induced Quantum Critical Point and Nodal Superconductivity in the Heavy-Fermion Superconductor Ce2PdIn8, Phys. Rev. X1, 011010 (2011). End Matter In this w...

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