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arxiv: 1906.09527 · v1 · pith:YTZWAIJHnew · submitted 2019-06-23 · ❄️ cond-mat.mes-hall

Observation of charge density wave transition in TaSe3 mesowires

J. Yang , Y. Q. Wang , R. R. Zhang , L. Ma , W. Liu , Z. Qu , L. Zhang , S. L. Zhang
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W. Tong L. Pi W. K. Zhu C. J. Zhang
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Pith reviewed 2026-05-25 18:20 UTC · model grok-4.3

classification ❄️ cond-mat.mes-hall
keywords TaSe3charge density wavemesowiresquasi-one-dimensionalsuperconductivityFermi surfacereduced dimensionality
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The pith

TaSe3 mesowires of 300 nm thickness exhibit a charge density wave transition at 65 K that is absent from bulk crystals.

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

The paper reports synthesis of TaSe3 mesowires and the first observation of a charge density wave transition at 65 K in wires roughly 300 nanometers thick. Resistivity shows a clear anomaly at this temperature, backed by Raman spectra and magnetic susceptibility data. Bulk TaSe3 crystals lack any resistivity signature of the transition yet display a switch from n-type to p-type carriers below 50 K in Hall measurements, hinting at Fermi surface reconstruction. The authors link the emergence of the CDW to the lowered dimensionality of the mesowires. They present TaSe3 as a platform for examining competition between charge density wave order and superconductivity in quasi-one-dimensional systems.

Core claim

In TaSe3 mesowires approximately 300 nm thick, a distinct charge density wave transition occurs at 65 K, detected in resistivity, confirmed by Raman characterization and susceptibility measurements. Bulk single crystals show no resistivity or magnetoresistance anomaly, but Hall effect measurements reveal a carrier-type change from n-type to p-type below 50 K, indicating Fermi surface reconstruction possibly tied to CDW. The CDW is enhanced in the mesowires relative to bulk because of reduced dimensionality.

What carries the argument

Reduced dimensionality in the mesowires, which stabilizes the Peierls instability and produces the observable CDW transition at 65 K.

If this is right

  • TaSe3 mesowires provide a single quasi-1D platform in which both CDW order and superconductivity can be examined together.
  • Lowering dimensionality in quasi-1D materials can make otherwise hidden CDW transitions detectable in transport.
  • Bulk TaSe3 may host an incipient CDW that reconstructs the Fermi surface without producing a clear resistivity signature.
  • Mesowire thickness offers a tunable parameter for controlling the strength of CDW order relative to other instabilities.

Where Pith is reading between the lines

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

  • Fabricating mesowires of other quasi-1D compounds could uncover suppressed CDW states in those materials as well.
  • Varying mesowire diameter may allow mapping of the boundary between CDW-dominated and superconductivity-dominated regimes.
  • The observed carrier-type reversal in bulk suggests Hall measurements can detect weak CDW signatures even when resistivity shows none.

Load-bearing premise

The resistivity anomaly at 65 K arises from a charge density wave transition caused by reduced dimensionality rather than another effect.

What would settle it

Spectroscopic measurements on the mesowires showing no energy gap or periodic lattice distortion opening at 65 K would falsify the CDW interpretation.

Figures

Figures reproduced from arXiv: 1906.09527 by C. J. Zhang, J. Yang, L. Ma, L. Pi, L. Zhang, R. R. Zhang, S. L. Zhang, W. K. Zhu, W. Liu, W. Tong, Y. Q. Wang, Z. Qu.

Figure 1
Figure 1. Figure 1: FIG. 1. (a) Schematic illustration of crystal structure of TaSe [PITH_FULL_IMAGE:figures/full_fig_p015_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. (a) [PITH_FULL_IMAGE:figures/full_fig_p016_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. (a) Raman [PITH_FULL_IMAGE:figures/full_fig_p017_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. (a) Temperature [PITH_FULL_IMAGE:figures/full_fig_p018_4.png] view at source ↗
read the original abstract

The quasi-one-dimensional (quasi-1D) TaSe3 attracts considerable attention for its intriguing superconductivity and possible interplay with nontrivial topology and charge density wave (CDW) state. However, unlike the isostructural analogues, CDW has not been observed for TaSe3 despite its quasi-1D character that is supposed to promote Peierls instabilities and CDW. Here we synthesize TaSe3 mesowires (MWs) using a one-step approach. For the MW of ~300 nm thick, a distinct CDW transition occurs at 65 K in the resistivity measurement, which has not been reported before and is further evidenced by the Raman characterization and susceptibility measurement. For comparison, we have also prepared bulk single crystal TaSe3. Although no anomaly appears in the resistivity and magnetoresistance measurements, the carrier type detected by Hall effect varies from n-type to p-type below 50 K, suggesting a reconstruction of Fermi surface that could be associated with CDW. The enhancement of CDW in the MWs is attributed to the reduced dimensionality. TaSe3 is demonstrated to be a promising platform to study the correlation and competition of CDW and superconductivity in the quasi-1D systems.

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

3 major / 2 minor

Summary. The manuscript reports synthesis of TaSe3 mesowires (~300 nm thick) via a one-step method and claims observation of a CDW transition at 65 K, manifested as a resistivity anomaly absent in bulk crystals. This is supported by Raman spectroscopy and magnetic susceptibility data on the mesowires; bulk samples show no resistivity anomaly but a Hall resistivity sign change from n- to p-type below 50 K, interpreted as possible Fermi-surface reconstruction. The CDW enhancement is attributed to reduced dimensionality, positioning TaSe3 mesowires as a platform for studying CDW-superconductivity interplay in quasi-1D systems.

Significance. If substantiated, the result would establish that mesowire geometry can induce a CDW state in TaSe3 where bulk crystals show none, offering a tunable quasi-1D platform for CDW-SC competition studies. The multi-probe approach (transport, Raman, susceptibility) on both mesowires and bulk provides a useful comparison, though the absence of direct structural confirmation limits the strength of the CDW assignment.

major comments (3)
  1. [Results on mesowire transport and Raman characterization] Transport and Raman sections: the 65 K resistivity feature is assigned to CDW without quantified signatures such as a gap opening, hysteresis, or superlattice peaks; the manuscript should explicitly address why impurity scattering, minor secondary phases, or measurement artifacts are excluded, given that resistivity anomalies alone are not diagnostic.
  2. [Bulk crystal transport and Hall measurements] Bulk vs. mesowire comparison: the Hall sign change occurs at 50 K while the mesowire resistivity anomaly is at 65 K; the text should clarify whether these are viewed as the same underlying transition (shifted by dimensionality) or distinct, and provide error bars or statistics on the transition temperatures.
  3. [Discussion section] Dimensionality argument: the claim that reduced dimensionality enhances CDW is not tested against thickness-dependent controls; data on mesowires of varying diameters (e.g., >500 nm) would be needed to establish a systematic trend rather than a single-thickness observation.
minor comments (2)
  1. [Abstract and Introduction] Abstract and introduction: the statement that CDW 'has not been observed for TaSe3' should cite the specific prior bulk studies that searched for it and found none.
  2. [Figures] Figure captions: ensure all panels include temperature labels, scale bars, and error bars where applicable; the susceptibility data should specify the applied field direction relative to the wire axis.

Simulated Author's Rebuttal

3 responses · 1 unresolved

We thank the referee for the constructive comments. We address each major point below and indicate where revisions will be made.

read point-by-point responses

  1. Referee: Transport and Raman sections: the 65 K resistivity feature is assigned to CDW without quantified signatures such as a gap opening, hysteresis, or superlattice peaks; the manuscript should explicitly address why impurity scattering, minor secondary phases, or measurement artifacts are excluded, given that resistivity anomalies alone are not diagnostic.

    Authors: We agree that resistivity anomalies require supporting evidence. The CDW assignment rests on the combination of the resistivity feature with Raman mode changes and susceptibility data. In revision we will add explicit discussion ruling out impurities and artifacts by noting sample reproducibility, measurement protocols, and the absence of similar features in bulk crystals. We cannot provide gap values or superlattice peaks with the present data set. revision: partial

  2. Referee: Bulk vs. mesowire comparison: the Hall sign change occurs at 50 K while the mesowire resistivity anomaly is at 65 K; the text should clarify whether these are viewed as the same underlying transition (shifted by dimensionality) or distinct, and provide error bars or statistics on the transition temperatures.

    Authors: We view the 65 K and 50 K features as related to the same CDW transition, with the modest temperature shift arising from dimensionality. The revised text will state this interpretation explicitly and include error bars derived from multiple samples. revision: yes

  3. Referee: Dimensionality argument: the claim that reduced dimensionality enhances CDW is not tested against thickness-dependent controls; data on mesowires of varying diameters (e.g., >500 nm) would be needed to establish a systematic trend rather than a single-thickness observation.

    Authors: The bulk-crystal comparison already functions as the limiting case of infinite thickness. Systematic variation of mesowire diameter is not feasible with the current one-step synthesis; we will add a limitations paragraph and note this as future work. revision: partial

standing simulated objections not resolved
  • Direct structural confirmation (superlattice peaks or diffraction evidence) of the CDW state is absent from the present data.

Circularity Check

0 steps flagged

No circularity: purely experimental observations with no derivation chain

full rationale

This is an experimental materials science paper reporting resistivity, Raman, Hall, and susceptibility data on TaSe3 mesowires versus bulk crystals. No equations, ansatzes, fitted parameters, or predictions are derived from prior results. The central claim (65 K anomaly as CDW) rests on direct measurements and comparison to bulk behavior, not on any self-referential reduction or self-citation load-bearing step. No instances of the enumerated circularity patterns exist.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

As an experimental observation paper, there are no free parameters, axioms, or invented entities in a theoretical sense. The interpretation relies on standard condensed matter physics assumptions about what constitutes a CDW transition.

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Reference graph

Works this paper leans on

5 extracted references · 5 canonical work pages

  1. [1]

    SEM images of TaSe3 MWs and characterizations

    work page

  2. [2]

    SEM images of TaSe3 MWs and characterizations FIG. S1. SEM images of the as-grown TaSe3 MWs with various diameters. FIG. S2. Single crystal XRD pattern of bulk TaSe3. FIG. S3. EDS result of TaSe3 MWs

    work page

  3. [3]

    SEM image of device FIG. S4. SEM image of a typical device with four probes used for electrical transport measurements. The contact and contact geometry are important to the performance of device. As was done in Ref. [1], we use a standard four probe technique to measure the resistivity of all samples. Figure S4 shows the SEM images of a typical device. T...

    work page

  4. [4]

    As shown in Fig

    Raman spectra To check the homogeneity of TaSe 3 MWs, we take Raman spectra at different locations on the same sample. As shown in Fig. S 5, all the spectra are highly resolved and consistent, suggesting good homogeneity. Hence, the structural inhomogeneity and defects in our samples are negligibly small. FIG. S5. Raman spectra taken at three different lo...

    work page

  5. [5]

    A. F. Isakovic, K. Cicak, and R. E. Thorne, Phys. Rev. B 77, 115141 (2008)

    work page 2008