# Pressure up to 2 GPa turns 6R-TaS2 superconductivity from nodal to nodeless, muon-spin data show

- Published: 2026-11-05 19:29 UTC
- Section: Science › Physics
- Tags: 6R-TaS2, tantalum disulfide, nodal superconductivity, superfluid density, muon-spin rotation, charge density wave, nonlinear Hall effect, hydrostatic pressure, Paul Scherrer Institute
- URL: https://realtech.media/news/rt-10f63f183f4efefda29125bb_pressure_up_to/

**Muon-spin rotation on a 6R-TaS2 single crystal shows superfluid density rising under pressure, the charge density wave onset halving and the nonlinear Hall effect vanishing.**

![Pressure up to 2 GPa turns 6R-TaS2 superconductivity from nodal to nodeless, muon-spin data show](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/b5aa246567b28b80.png)
*nature.com*

Researchers at the Paul Scherrer Institute (PSI) in Switzerland, led by Zurab Guguchia, studied the layered transition metal dichalcogenide 6R-TaS2 with muon-spin rotation, magnetotransport and hydrostatic pressure up to 2 GPa. The work, described on nature.com and published in Nature Communications, identifies a nodal superconducting state with low superfluid density at ambient pressure [1]. Under pressure the pairing becomes nodeless [1].

## Material and open questions

6R-TaS2 is a bulk heterostructure of alternating trigonal prismatic (1H) and octahedral (1T) layers. Earlier studies found a charge density wave (CDW) transition at about 305 K and a bulk superconducting transition at about 2.6 K, determined from magnetization measurements [1]. Superconductivity was proposed to reside mainly in the 1H layers, separated by insulating 1T layers in the CDW state [1].

Below T* of about 40 K the material shows pronounced magnetoresistance and a nonlinear Hall effect (NHE), which had been interpreted as a sign of hidden magnetism [1]. The gap symmetry, the superfluid density, the origin of the NHE and its relation to the CDW remained undetermined [1].

## What pressure changed

Muon-spin rotation detected no spontaneous magnetic order below T*. According to the authors, this rules out magnetism as the origin of the NHE [1].

At pressures up to 2 GPa the superfluid density rises markedly, in correlation with the superconducting transition temperature. The nodal pairing shifts to a nodeless state, and the CDW onset is reduced by half [1]. The NHE is fully suppressed and the magnetoresistance drops by 50% within just 0.2 GPa, which the authors take as evidence of the fragility of the state with the NHE [1].

The authors conclude that superconductivity, charge order and the nonlinear Hall effect compete in 6R-TaS2, driven by weakened interlayer coupling and shared electronic states [1]. In the PSI team's account, compression brings the superconducting layers closer together and lets electrons localized in the insulating layers take part in superconductivity; they also report a sevenfold increase in the number of electrons involved.

## Sources

1. [nature.com](https://www.nature.com/articles/s41467-026-72136-x)
2. [SciTechDaily](https://scitechdaily.com/scientists-unlock-a-hidden-superconducting-power-inside-a-strange-quantum-material)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-10f63f183f4efefda29125bb_pressure_up_to/