Executive Summary

Researchers at the Paul Scherrer Institute PSI, led by Zurab Guguchia, have investigated the quantum material tantalum disulfide and discovered a crucial mechanism of superconductivity under pressure. Using muon spin spectroscopy, they demonstrated that high pressure increases the temperature at which the material becomes superconducting by a factor of three, while simultaneously increasing the number of participating electrons by a factor of seven. The results were published on July 7, 2026 in Nature Communications and point toward a path to practically usable superconductors.

People

  • Zurab Guguchia (Research Group Leader, PSI Center for Neutron and Muon Sciences)

Topics

  • Superconductivity and quantum materials
  • Pressure-induced phase transitions
  • Muon spin spectroscopy
  • Energy efficiency and future technologies

Clarus Lead

The discovery addresses a central obstacle to the use of superconductors in the energy industry: their dependence on extreme cooling. While previous superconductors only function at temperatures near absolute zero and are therefore technically demanding, the PSI study reveals a physical mechanism that enables higher operating temperatures. This brings the long-term goal—superconductors at room temperature—closer and could accelerate the development of energy-efficient power grids and transport technologies.

Detailed Summary

Tantalum disulfide possesses an unusual crystal structure consisting of alternating layers with opposing electronic properties. At room temperature, both layers conduct current, but upon cooling, one layer becomes insulating while the other becomes superconducting. Only at temperatures near absolute zero (approximately 1 Kelvin) does the entire material become three-dimensionally superconducting, as the insulating layers become conductive again.

The PSI team subjected the material to extreme pressures—several hundred times higher than atmospheric pressure—and analyzed electron behavior using muon spin spectroscopy, a method in which elementary particles (muons) serve as highly sensitive magnetic probes. The PSI operates the Swiss Muon Source SμS, the world's strongest muon source, and thus possesses unique experimental capabilities. Under pressure, the crystal planes compress, causing two effects: the superconducting layers move closer together and are less disrupted by the insulating barriers; simultaneously, electrons are released from the insulating layer and can participate in superconductivity. This results in the critical temperature rising from approximately 1 Kelvin to around 3 Kelvin, and electron participation increasing by a factor of seven. Guguchia emphasizes that pressure not only raises the temperature but fundamentally alters the nature of the superconducting state—the way electrons pair up into stable pairs and move together through the material becomes more robust.

Key Findings

  • High pressure increases the superconducting transition temperature of tantalum disulfide by a factor of three and increases the number of superconducting electrons by a factor of seven.
  • The pressure effect is based on two mechanisms: reduction of insulating barriers between superconducting layers and release of additional charge carriers.
  • The findings provide theoretical physicists with precise data for optimizing quantum materials for higher operating temperatures.

Critical Questions

  1. Evidence: How robust are the muon measurements under extreme pressure? Have the results been confirmed by independent laboratories or alternative measurement methods, or do they rely solely on PSI data?

  2. Scalability: The experiments show effects at pressures of several hundred bar—is practical application realistic if such pressures must be maintained continuously?

  3. Material Selection: Why was tantalum disulfide chosen as a model system? Are there other material classes in which similar pressure effects are more pronounced or occur at lower pressures?

  4. Timeline: The publication mentions the IMPACT upgrade and the National Research Program Muoniverse—what concrete progress is expected in the next 3–5 years, and how likely is the approach to room-temperature superconductivity?

Source Directory

Primary Source:

Competing quantum orders in 6R-TaS₂ revealed by pressure – Nature Communications, 07.07.2026 | DOI: 10.1038/s41467-026-72136-x

Institutional Source:

Paul Scherrer Institute PSI – Press Release

Verification Status: ✓ 07.07.2026

This text was created with the support of an AI model. Editorial Responsibility: clarus.news | Fact-Check: 07.07.2026