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arxiv: 2404.15924 · v1 · submitted 2024-04-24 · ❄️ cond-mat.str-el

Emergent Topological Semimetal

D. M. Kirschbaum , L. Chen , D. A. Zocco , H. Hu , F. Mazza , J. Larrea Jim\'enez , A. M. Strydom , D. Adroja
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X. Yan A. Prokofiev Q. Si S. Paschen
This is my paper

Pith reviewed 2026-05-24 01:50 UTC · model grok-4.3

classification ❄️ cond-mat.str-el
keywords topological semimetalquantum critical pointheavy fermionKondo destructionCeRu4Sn6Weyl-Kondo semimetalspectral function
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The pith

A topological semimetal phase emerges from the quantum critical state of CeRu4Sn6 even without quasiparticles.

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

The paper examines how interactions enrich electronic topology in metals when quasiparticles are absent, using the heavy-fermion compound CeRu4Sn6 at its quantum critical point. It reports the discovery of a topological semimetal phase that appears as a dome in magnetic field and pressure. To interpret the data, the authors analyze a Weyl-Kondo semimetal model at the Kondo destruction quantum critical point, where the spectral function shows features that mark topological crossings outside the quasiparticle framework. The work suggests that such emergent topological phases may occur more broadly in quantum critical materials.

Core claim

In CeRu4Sn6, a topological semimetal phase emerges directly from the quantum critical state and forms a dome as a function of magnetic field and pressure. A Weyl-Kondo semimetal model at the Kondo destruction quantum critical point reproduces features in the spectral function that define topological crossings beyond the quasiparticle picture.

What carries the argument

The spectral function of the Weyl-Kondo semimetal model evaluated at the Kondo destruction quantum critical point, whose features mark topological crossings without requiring quasiparticles.

If this is right

  • The emergent phase appears only near the quantum critical point and vanishes away from it in field-pressure space.
  • Topological crossings can be identified from spectral features without invoking well-defined quasiparticles.
  • Similar emergent topological phases are expected in other heavy-fermion compounds tuned through a Kondo destruction transition.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The result suggests that topology in strongly interacting metals can be diagnosed directly from Green's functions at criticality rather than from band topology alone.
  • Experimental searches could target other Kondo lattice materials near their quantum critical points for analogous domes in transport or spectroscopy.

Load-bearing premise

Features seen in the spectral function at the Kondo destruction quantum critical point can be read as topological crossings even though no quasiparticles exist.

What would settle it

Absence of the reported dome structure in resistivity or Hall data under combined magnetic field and pressure, or lack of corresponding crossings in the model's spectral function at the critical point.

Figures

Figures reproduced from arXiv: 2404.15924 by A. M. Strydom, A. Prokofiev, D. Adroja, D. A. Zocco, D. M. Kirschbaum, F. Mazza, H. Hu, J. Larrea Jim\'enez, L. Chen, Q. Si, S. Paschen, X. Yan.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p008_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p010_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p011_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5 [PITH_FULL_IMAGE:figures/full_fig_p012_5.png] view at source ↗
read the original abstract

A material's electronic topology, which is generally described via its Bloch states and the associated bandstructure, will be enriched by the presence of interactions. In metallic settings, the interactions are usually treated through the concept of quasiparticles. Using the genuinely quantum critical heavy fermion compound CeRu$_4$Sn$_6$, we investigate what happens if no well-defined quasiparticles are present. Surprisingly, we discover a topological semimetal phase that emerges from the material's quantum critical state and exhibits a dome structure as a function of magnetic field and pressure. To understand these results, we study a Weyl-Kondo semimetal model at a Kondo destruction quantum critical point. Indeed, it exhibits features in the spectral function that can define topological crossings beyond the quasiparticle picture. We expect our work to stimulate the search for other emergent topological phases.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 1 minor

Summary. The manuscript reports the experimental discovery of an emergent topological semimetal phase in the quantum critical heavy-fermion compound CeRu₄Sn₆ that forms a dome structure in magnetic field and pressure. This is supported by a theoretical study of a Weyl-Kondo semimetal model at the Kondo destruction quantum critical point, where features in the spectral function are interpreted as defining topological crossings beyond the quasiparticle picture.

Significance. If the central claim holds, the work would be significant for extending topological band concepts to strongly interacting regimes without well-defined quasiparticles. The combination of experimental dome observation in CeRu₄Sn₆ with the model spectral-function analysis provides a concrete platform that could stimulate searches for other emergent topological phases in quantum critical materials.

major comments (1)
  1. [Theoretical Model / Abstract] The central claim that spectral-function features at the Kondo destruction QCP constitute topological crossings (abstract and model section) lacks a defined topological invariant. Standard classification requires Berry curvature monopoles or Z₂ invariants on quasiparticle bands or poles of the Green's function; no frequency-dependent winding number or equivalent quantized quantity from the interacting Green's function is shown to be protected or quantized. This step is load-bearing because the model result is used to interpret the experimental dome.
minor comments (1)
  1. [Abstract] The abstract states that the model 'exhibits features in the spectral function that can define topological crossings' but does not specify the precise features (e.g., node locations, dispersion, or intensity) or how they map to the experimental phase diagram.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading of the manuscript and for the positive assessment of its potential significance. We address the single major comment below.

read point-by-point responses

  1. Referee: [Theoretical Model / Abstract] The central claim that spectral-function features at the Kondo destruction QCP constitute topological crossings (abstract and model section) lacks a defined topological invariant. Standard classification requires Berry curvature monopoles or Z₂ invariants on quasiparticle bands or poles of the Green's function; no frequency-dependent winding number or equivalent quantized quantity from the interacting Green's function is shown to be protected or quantized. This step is load-bearing because the model result is used to interpret the experimental dome.

    Authors: We agree that the manuscript does not compute an explicit topological invariant (such as a frequency-dependent winding number or Berry curvature monopole) for the interacting Green's function at the Kondo destruction QCP. The interpretation in the model section rests on the persistence of spectral-function crossings that are topologically protected in the non-interacting Weyl-Kondo limit and remain visible in the critical regime of the model. While this provides a physically motivated connection to the experimental dome, it does not constitute a rigorous topological classification in the fully interacting case. We will revise the abstract and model section to clarify this distinction and to state explicitly that the topological character is inferred from continuity with the Weyl-Kondo semimetal rather than proven via a quantized invariant of the interacting Green's function. This revision will also adjust the language used to interpret the experimental results. revision: yes

Circularity Check

0 steps flagged

No circularity: experimental observation + independent model study

full rationale

The provided abstract and context show an experimental discovery of a dome-shaped topological semimetal phase in CeRu4Sn6 emerging from its quantum critical state, followed by a separate study of the Weyl-Kondo semimetal model at the Kondo destruction QCP. The model is reported to exhibit spectral function features that 'can define topological crossings beyond the quasiparticle picture.' No equations, self-citations, or derivations are quoted that reduce a claimed prediction or invariant to a fitted input, self-definition, or prior author result by construction. The interpretation step is presented as an independent insight rather than a tautological renaming or load-bearing self-reference. The derivation chain remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract supplies no explicit free parameters, axioms, or invented entities; the Weyl-Kondo model is invoked but its internal assumptions are not listed.

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Reference graph

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