Superleitfähigkeit Beschränkungen

Electricity has been one of the most transformative technologies in history, allowing for the transmission of a very useful form of energy over long distances. But every “normal” electric system faces electric resistance, which results in the generation of heat when an electric current is applied.

Eine Alternative existiert: die sogenannten supraleitenden Materialien. Supraleitende Materialien besitzen einen elektrischen Widerstand von null, was extrem starke Ströme ermöglicht, ohne dass Wärme entsteht.

Ohne Supraleitung wäre vieles der modernen Technologie nicht möglich, darunter Teilchenbeschleuniger (zum Beispiel das CERN), MRT und Magnetschwebebahnen.

Supraleitung wird ein entscheidender Baustein der vielversprechendsten Megaprojekte und technologischen Innovationen sein, wie ITER und Kernfusion, Massenantriebe, Quantencomputer usw.

Stromleitungen ohne Verluste könnten ebenfalls entscheidend sein, um ultra‑lange Netzanbindungen zu entwickeln, die die Produktion erneuerbarer Energien über Wetterbedingungen und Zeitzonen hinweg puffern und einige der Beschränkungen von Solar‑ und Windenergie lösen.

Das Problem bisher ist, dass all diese Anwendungen auf Niedertemperatur‑Supraleitung basieren, bei der die Materialien nur supraleitend sind, wenn sie auf sehr niedrige Temperaturen wie 20 K / ‑253 °C / ‑423 °F gekühlt werden, was in der Regel flüssiges Helium erfordert.

This makes it not only too complex for any but the most demanding applications (maglev, MRI, etc.) but also very costly, making it uneconomical for many applications that could benefit from superconductive material or any large-scale use.

Viele Wege zur Supraleitung

Other forms of superconductivity than ultra-cold materials require constant very high pressure for the material to stay superconductive. This might be interesting from an experimental point of view, but even less practical for industrial applications or in energy and transportation infrastructures.

Hochtemperatur‑Supraleitung könnte eine Option werden, insbesondere mit dem rätselhaften Fall von LK-99 (eine Form von kupferersetztem Bleiapatit – CSLA), einem neuen Typ von druckfreiem, raumtemperatur‑Supraleiter. Die Behauptung wurde sofort angezweifelt und als Schwindel oder Messfehler kritisiert, doch später entdeckten andere Forscher, dass doch etwas dahinterstecken könnte.

Jedenfalls zeigt der Fall LK-99, dass wir noch weit davon entfernt sind, alles zu wissen, was Supraleitung möglich macht.

Kürzlich erschien twisted bilayer of WSe₂ (tungsten selenide) ebenfalls als vielversprechender Materialkandidat.

Forscher an der University of Houston, University at Buffalo, University of Illinois, National Sun Yet‑Sen University (Taiwan) und Intellectual Venture erweitern das Feld möglicher supraleitender Materialien und entfernen die Notwendigkeit von hohem Druck, außer während der Herstellung des Materials.

They published their results¹ in the Proceedings of the National Academy of Sciences (PNAS), under the title “Creation, stabilization, and investigation at ambient pressure of pressure-induced superconductivity in Bi0.5Sb1.5Te3”.

Supraleitung & Druck

The connection between high pressure and superconductivity has been studied for more than 30 years now, since their initial discovery in 1993. What happens is that the pressure modifies the atomic behavior of the material, which itself affects its electrical properties.

“In 2001, scientists suspected that applying high pressure to BST changed its Fermi surface topology, leading to improved thermoelectric performance.

That connection between pressure, topology, and superconductivity piqued our interest.”

Pr. Liangzi Deng – Researcher at the University of Houston

Pr. Deng (left) and Pr. Chu (right) – Source: University of Houston

The problem is that for a material to be useful for industrial applications, it usually needs to display interesting properties when in a metastable state, so it can hold these properties in “normal” conditions.

So far, the requirement of very high pressure has not only hindered the study of materials superconductive in these conditions, but also made very elusive any future practical applications, as it would not work to keep a cable, magnet, or railroad component under such extreme pressure conditions, even less than the ultra-cold conditions requirement for the superconductors currently used.

Hochdruck‑Abschrecken

Maintaining the superconductivity properties at normal pressure is what the researchers just achieved.

To do so, they used a special semiconductor material called  BST (Bismuth-Antimony-Tellurium / Bi_0.5Sb₁.5Te₃). Under pressures up to ~50 GPa (Gigapascal), or 500,000x stronger than atmospheric pressure (1 bar), BST displays three superconducting phases (BST-I, -II, and -III), with the first one appearing at 4 GPa.

The researchers developed a procedure called pressure-quench protocol (PQP), allowing for the pressure-induced phase to persist at room pressure.

Not only was the BST-I superconducting phase preserved, but also the BST-II and -III phases.

They used a diamond anvil to reach the extreme pressure required.

Source: University of Houston

The electric and magnetic properties were analyzed using a very sensitive instrument called Magnetization Property Measurement System (MPMS)

Source: University of Houston

Verbesserung der Arbeitstemperatur

When tested, these superconducting phases were not only initially stable at room pressure, but also preserved these states over time and when exposed to higher temperatures.

This, however, does not mean this is a room-temperature superconductor, only that the phases are stable in normal pressure and able to display actual superconductivity when cooled down.

BST is known to display superconductivity at 10.2°K (-262.9°C / -441.3°F). The researchers found that the depressurization and the pressure-quench protocol both improved BST’s transition temperature, making it a good option for improving existing superconductive materials.

“This experiment clearly demonstrates that one may stabilize the high-pressure-induced phase at ambient pressure via a subtle electronic transition without a symmetry change, offering a novel avenue to retain the material phases of interest and values that ordinarily exist only under pressure.

Pr. Paul Chu – Researcher at the University of Houston

Zukünftige Anwendungen

While not immediately creating superconductive material, this opens the way for a new method to discover and design superconductive materials.

Until now, high-pressure superconductivity had very few practical applications, and a room-temperature superconductor had to display this characteristic independent of the effect of pressure.

If the pressure-quench protocol can be generalized, this could help stabilize in normal conditions superconductive materials that are promising, but so far only worked at high pressure.

“Interestingly, this experiment revealed a novel approach to discovering new states of matter that do not exist at ambient pressure originally or even under high-pressure conditions.

It demonstrates that PQP is a powerful tool for exploring and creating uncharted regions of material phase diagrams.”

Pr. Liangzi Deng – Researcher at the University of Houston

It could also improve known superconductors so that their transition temperature is higher.

This could open the way for successive states, making it possible to create a superconductor that can work with “just” 78°K (-195°C / -319°F), or the boiling point of liquid nitrogen, a much easier-to-handle coolant than liquid helium, which is for example currently used in the superconducting magnets of ITER.

Supraleitungsunternehmen

American Superconductor Corporation

AMSC is a company providing energy solutions for the power grid, ships, and wind energy. In general, the more power-hungry or massive a system is, the more it requires superconducting technology to avoid overheating.

Despite its name, ASMC provides not only superconductor systems but also, for example, gear drivetrains for wind turbines.

The company is riding multiple growth drivers, from the trend of electrification, and digitalization (including AI datacenters), but also the reshoring of US manufacturing capacities and the need for Navies of the Anglosphere to modernize in response to growing geopolitical risks.

Source: American Superconductor Corporation

In the power supply segment, AMSC has seen a steady rise in orders. This was driven by semiconductor fabs looking to be protected from power grid fluctuations, helping the grid deal with the intermittent nature of renewables, and power supply & controls at industrial sites.

Source: American Superconductor Corporation

In the wind turbine segment, AMSC is mostly active with Electrical Control System (ECS). Historically, ESC was a strong segment for the company with the 2MW wind turbines, but it has progressively declined. AMSC aims for a rebound thanks to the new 3MW turbine design, with a special focus on the Indian market.

Source: American Superconductor Corporation

For military ships, ASMC provides the “AMSC’s High Temperature Superconductor Magnetic Mine Countermeasure “, a system to alter the magnetic signature of the ships to protect them from sea mines. This is sold to the US, Canadian, and UK navies, with $75M worth of orders so far.

Overall, ASMC is doing best with leveraging superconductor technology in niche applications viable today, while likely being ready to deploy further advances in the future. It should also be noted by investors that the stock has experienced extreme volatility in the past, and to calculate the risks accordingly.

Studienreferenz:

^{1.Deng, B. et al, (2025) Erzeugung, Stabilisierung und Untersuchung bei Umgebungsdruck von druckinduzierter Supraleitung in Bi0.5Sb1.5Te3. Proc. Natl. Acad. Sci. U.S.A. 122 (6) e2423102122, https://doi.org/10.1073/pnas.2423102122}