Cómo los científicos hicieron que los semiconductores fueran superconductores

Límites de la superconductividad

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.

An alternative exists: superconductive materials. Superconducting materials have zero electrical resistance, allowing extremely powerful currents to flow without generating heat.

Without superconductivity, plenty of modern technology would not be possible, including particle accelerators (for example, CERN), MRI, and maglev trains.

Superconductivity will be a crucial component of the most promising megaprojects and technological innovations, like ITER and nuclear fusion, mass drivers, quantum computers, etc.

Zero-loss electric power lines could also be crucial in developing ultra-long grid connections, helping buffer the production of renewables over weather conditions and time zones, solving some of the limitations of solar and wind power.

However, superconductivity has been mastered so far only for materials displaying it at ultra-low temperatures, barely a few degrees above absolute zero. Or extremely high pressure. Or both.

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

Muchas rutas hacia la superconductividad

It now seems that the material produced under high pressure might be able to retain some of its superconductivity at lower pressure through an experimental method called pressure-quench protocol (PQP).

Recently, the twisted bilayer of WSe₂ (tungsten selenium) appeared to be a good material candidate for higher-temperature superconductors as well.

Another new class of potential superconductors, bilayer nickelates, might have been added to the list this year as well.

Still, all of these materials are relatively new and exotic, making them rather far from mass production and deployment at scale.

This could change, thanks to the discovery that germanium-based semiconductors could be turned into superconductors. This research was done by scientists at the University of Queensland (Australia), New York University, ETH Zürich (Switzerland), and The Ohio State University, who published their findings in Nature Nanotechnology¹, under the title “Superconductivity in substitutional Ga-hyperdoped Ge epitaxial thin films”.

De semiconductores a superconductores

Semiconductores de germanio

Germanium and silicon are both so-called Group IV elements, with diamond-like crystal structures. This crystalline structure makes them behave as something between a metal (conductive of electricity) and an insulator (non-conductive), making them useful for semiconductor production.

Germanium semiconductor production is already well understood and performed at scale for various electronic and optical devices. En realidad, fue uno de los primeros materiales utilizados para diodos y transistores, y solo fue reemplazado por el silicio gracias a sus menores costos y superior estabilidad térmica.

Today, germanium, which is crucial for electronics and infrared optics, including sensors on missiles and defense satellites, is mostly produced from zinc and molybdenum mines.

To create superconductivity, you need electrons to pair up, letting them move through the material without resistance.

Ya en 2023, se encontró una fase superconductora en películas de germanio, a work conducted by the researchers responsible for this latest discovery, doping gallium material with germanium.

Fuente: ResearchGate

“Esto funciona porque los elementos del grupo IV no se vuelven superconductores de forma natural bajo condiciones normales, pero modificar su estructura cristalina permite la formación de emparejamientos de electrones que permiten la superconductividad.”

Javad Shabani – Director del Center of Quantum Information Physics de NYU.

Potencial de escalado

While previous attempts to create superconducting behavior in semiconductors such as germanium and silicon proved the concept, they struggled to build it at scale.

The main issues were to maintain the atomic structure with appropriate conduction properties. Normally, high levels of gallium destabilize the crystal, preventing superconductivity.

Still, this is a promising idea, as germanium semiconductor manufacturing is a very well-understood technology, with plenty of equipment ready to use.

“El germanio ya es un material básico para tecnologías avanzadas de semiconductores, así que al demostrar que también puede volverse superconductor bajo condiciones de crecimiento controladas, ahora existe el potencial para dispositivos cuánticos escalables y listos para fundiciones.”

Dr Peter Jacobson – Investigador de la University of Queensland

Nuevo método de producción

Most doping methods try to implement the ions into the material, but lead to rather irregular results. While that can be enough to improve semiconductor performance, this is too imprecise to induce superconductivity.

Instead, the researchers used a technique called epítaxis por haz molecular (MBE). Dirige beams of atomic or molecular sources onto a heated substrate in an ultra-high vacuum (UHV) environment.

Fuente: ExplainThatStuff

This gives precise control over the composition, thickness, and doping of the growing film.

“En lugar de la implantación de iones, se utilizó epítaxis por haz molecular (MBE) para incorporar con precisión átomos de galio en la red cristalina del germanio.

El uso de la epitaxia – el crecimiento de capas cristalinas delgadas – significa que finalmente podemos lograr la precisión estructural necesaria para comprender y controlar cómo emerge la superconductividad en estos materiales.”

Dr Julian Steele – Investigador de la University of Queensland

When using synchrotron-based X-ray absorption, the researchers found that gallium dopants are incorporated within the germanium lattice, introducing a tetragonal distortion to the crystal unit cell.

Fuente: Nature Nanotechnology

This structural order creates a narrow electronic band for the emergence of superconductivity in Ge.

Fuente: Nature Nanotechnology

More importantly, this method can work at the wafer-level scale, the same methods used to mass-produce electronics chips.

Fuente: WaferWorld

“Este trabajo teórico confirmó que los átomos de galio se sustituyen limpiamente en la red de germanio, creando las condiciones electrónicas para la superconductividad.

Es un ejemplo elegante de cómo la computación y el experimento juntos pueden resolver un problema que ha desafiado a la ciencia de materiales durante más de medio siglo.”

Dr Carla Verdi – Investigadora de la University of Queensland

Aplicaciones

The superconductivity this method creates is not a room-temperature superconductivity, as it requires temperatures as low as 3.5°K (-269°C / -453°F), a phenomenon still eluding material science.

Still, the ease of its production, using well-established machinery used by the semiconductor industry, could radically change how superconducting chips are made.

In turn, this could radically change how materials for quantum computers are produced. Most likely, instead of expensive superconducting material, a future quantum computer could be just using a “normal” gallium-germanium semiconductor wafer, turned superconducting in specific spots of the chip.

“These materials opens a pathway for a new era of hybrid quantum devices and could underpin future quantum circuits, sensors and low-power cryogenic electronics, all of which need clean interfaces between superconducting and semiconducting regions.”

Dr Peter Jacobson – Researcher at University of Queensland

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Invertir en la fabricación de semiconductores

TSMC

Semiconductor production is an industry dominated by the combination of very niche and complex expertise, and the need to mass-produce at scale to reduce costs.

No company has been as successful at mastering this business model as TSMC, the Taiwanese company leading the world in the manufacturing of ultra-advanced chips.

TSMC produces, of course, mostly silicon chips, including the most powerful 3 and 2nm node chips. And as it produces mostly the most advanced and expensive chips, it controls more than half of the global revenues of the semiconductor foundry industry.

Fuente: Eric Flaningam

TSMC is today evolving to start producing silicon chips in the US, notably with a massive investment in its new Arizona foundries.

Still, TSMC is also an expert at advanced germanium-based transistors and other semiconductors.

So while the company is mostly driving its current profit from advanced chips and the manufacturing of AI-hardware for the likes of Nvidia (NVDA ), it could also be one of the main beneficiaries of the discovery that common semiconductor manufacturing methods can produce.

Últimas noticias y desarrollos de acciones de TSMC (TSM)

Estudio Referenciado:

^{1. Steele, J.A., Strohbeen, P.J., Verdi, C. et al. Superconductivity in substitutional Ga-hyperdoped Ge epitaxial thin films. Nat. Nanotechnol. (2025). https://doi.org/10.1038/s41565-025-02042-8}