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arxiv: 2607.00765 · v1 · pith:HGRT7MAMnew · submitted 2026-07-01 · ❄️ cond-mat.supr-con · cond-mat.str-el

Resilient j=3/2 superconductivity in topological semimetal YPtBi

Prathum Saraf , Nicholas A. Crombie , Rahul Sharma , Jared Z. Dans , Danila Sokratov , Carsyn L. Mueller , Ram Kumar , Hyunsoo Kim
show 6 more authors
Connor Roncaioli Winslow Weiss David Graf Chandra Shekhar Claudia Felser Johnpierre Paglione
This is my paper

Pith reviewed 2026-07-02 04:09 UTC · model grok-4.3

classification ❄️ cond-mat.supr-con cond-mat.str-el
keywords superconductivitytopological semimetalYPtBij=3/2 pairingdisorder effectscarrier densityphase stiffness
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The pith

The critical temperature of superconductivity in YPtBi shows little variation despite large changes in disorder and carrier density.

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

This paper investigates the effects of disorder and carrier density on superconductivity in the topological semimetal YPtBi. The material features j=3/2 quasiparticles near the Fermi level due to band inversion and strong spin-orbit coupling. Experiments show that Tc remains robust across nearly two orders of magnitude in disorder and three in carrier density. This suggests the transition is controlled by phase stiffness rather than the pairing interaction itself. The finding points to a novel protection mechanism in high-spin topological superconductors.

Core claim

Cooper pairing in YPtBi occurs among j=3/2 quasiparticle states. By varying magnetic and nonmagnetic disorder by nearly two orders of magnitude and carrier densities by three orders, the superconducting critical temperature exhibits remarkable robustness with little variation. The results suggest that superconductivity resides in a regime where phase stiffness, rather than pair formation, governs the transition temperature. The insensitivity of Cooper pairing to dramatic changes in the quasiparticle environment highlights a new form of protection in topological high-spin superconductors.

What carries the argument

The j=3/2 quasiparticle manifold at the Gamma point, which supports resilient superconducting pairing insensitive to variations in the quasiparticle environment.

If this is right

  • Superconductivity in YPtBi is protected against substantial changes in disorder and carrier concentration.
  • The transition temperature is likely limited by phase stiffness rather than the strength of the pairing interaction.
  • This resilience represents a distinct protection mechanism for topological high-spin superconductors.
  • Pairing in such systems can persist even as the electronic environment near the Fermi level is strongly modified.

Where Pith is reading between the lines

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

  • Similar robustness could be tested in other topological semimetals with inverted bands and high-spin states.
  • If phase stiffness dominates, then Tc might be increased by improving superfluid density without needing stronger pairing.
  • Device applications of such superconductors could tolerate variations in material quality better than conventional ones.

Load-bearing premise

The changes in disorder and carrier density accurately and independently control the quasiparticle environment near the Fermi level without introducing confounding factors such as sample inhomogeneity.

What would settle it

Observing a significant dependence of the critical temperature on disorder or carrier density in high-quality samples where other variables are held constant would contradict the claimed robustness.

Figures

Figures reproduced from arXiv: 2607.00765 by Carsyn L. Mueller, Chandra Shekhar, Claudia Felser, Connor Roncaioli, Danila Sokratov, David Graf, Hyunsoo Kim, Jared Z. Dans, Johnpierre Paglione, Nicholas A. Crombie, Prathum Saraf, Rahul Sharma, Ram Kumar, Winslow Weiss.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: (a) presents the weaker quantum oscillations observed in disordered samples. Although the oscilla￾tions are less prominent due to increased scattering, the background-subtracted oscillatory component is indeed periodic in 1/µ◦H, as shown in the inset. The FFT in [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: (c)). The presence of superconductivity in both the dilute and heavily doped metallic regimes suggests that the pairing mechanism is not only robust but fundamen￾tally distinct from any other known superconductor. This behavior supports the idea that superconduc￾tivity in YPtBi is not tied to a fine-tuned Fermi sur￾face instability or a high density of states at the Fermi level, but rather an alternative m… view at source ↗
read the original abstract

Cooper pairing in most of the known fermionic superfluids occurs via spin-1/2 quasiparticle interactions that lead to spin-singlet or spin-triplet pairing. In the topological semimetal YPtBi, strong spin-orbit coupling results in a band inversion between highly symmetric $s$- and $p$-like electronic bands and a degeneracy at the $\Gamma$ point that ensures the manifold of $j$=3/2 quasiparticle states thrive near the Fermi level, where superconducting pairing occurs. Here we study the effects of magnetic and nonmagnetic disorder and carrier density on this exotic superconducting pairing state. By varying levels of disorder and carrier densities by nearly two and three orders of magnitude, respectively, we show that the superconducting critical temperature of YPtBi has a remarkable robustness, with little variation across this span. Our results suggest that superconductivity in YPtBi may reside in a regime where phase stiffness, rather than pair formation, governs the transition temperature. The insensitivity of Cooper pairing to dramatic changes in quasiparticle environment in a $j$=3/2 superconductor highlights a new form of protection realized in topological high-spin superconductors.

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.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Experimental study; no new theoretical parameters, axioms, or entities introduced beyond standard condensed-matter assumptions about superconductivity and topological band structure.

pith-pipeline@v0.9.1-grok · 5796 in / 1037 out tokens · 28206 ms · 2026-07-02T04:09:34.973712+00:00 · methodology

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Reference graph

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