(ORDO NEWS) — By replacing a classical material with a material with unique quantum properties, scientists have created a superconducting circuit capable of feats long thought impossible.
The discovery, made by researchers in Germany, the Netherlands and the United States, has upended centuries-old ideas about the nature of superconducting circuits and how their currents can be tamed and used in practice.
Low-waste, high-speed circuits based on the physics of superconductivity represent a golden opportunity to take supercomputing technology to a whole new level.
Unfortunately, the characteristics that make this mild form of electrical current so convenient also create endless challenges when designing superconducting versions of conventional electrical components.
Take, for example, such a simple element as a diode. This basic element of electronics is like a one-sided sign for currents, providing a means to regulate, transform, and tune the movement of electrons.
In superconducting materials, the identity of these individual electrons is blurred, resulting in partners called Cooper pairs, giving each particle in this partnership the chance to escape the energetic jolts associated with conventional electric current.
But without the usual laws of resistance, scientists have been unable to get superconducting electrons to move in the same direction, as they always exhibit what is called “reciprocal” behavior.
This fundamental assumption that superconductivity cannot violate reciprocity (at least not without magnetic field manipulation) – has been maintained since the beginning of research in this area.
Frankly, this is an obstacle that engineers could do without.
“In the 1970s, IBM scientists tried to realize the idea of superconducting computing, but were forced to stop their attempts: in their works on this topic, IBM mentions that without non-reciprocal superconductivity, a computer running on superconductors is impossible,” the researchers explain in a press statement. about your new research.
These efforts may now have to be reconsidered after an experiment that demonstrated a type of transition with a quantum component capable of guiding even Cooper vapors down a one-way street.
Josephson junctions are thin strips of non-superconducting material that separate a pair of materials that are superconductors. If the material is thin enough, then electrons can pass through it unhindered.
Below a certain level, this “overcurrent” has no voltage. At the critical point, a voltage is generated that rapidly oscillates in waves that can be used in applications such as quantum computers.
To ensure that this current went only in one direction, it was previously possible with the help of an external magnetic field. But the team found that if they used a two dimensional lattice based on the metal niobium, they could forego the field and rely solely on the quantum properties of the material.
“We were able to peel off just a couple of atomic layers of this Nb3Br8 and make a very, very thin sandwich – just a few atomic layers thick – which was necessary to create a Josephson diode, and which was not possible with conventional 3D materials,” says lead researcher Mazhar Ali, a physicist. from the Delft University of Technology in the Netherlands.
The team is confident that they have ticked all the boxes needed to make a compelling case for their discovery. However, there is a long way to go before we see superconductors at the heart of next-generation computing systems.
First, the phenomenon of superconductivity usually occurs in materials cooled to a temperature just above absolute zero.
Some superconducting materials can handle heat, but only if they’re placed under insane pressure.
Studying how Josephson junctions based on these new quantum barriers operate at higher temperatures and pressures could eventually become a game changer, reducing the amount of hardware required for incredibly efficient supercomputers the likes of which the world has never seen before.
“This will affect all sorts of social and technological applications,” says Ali.
“If the 20th century was the century of semiconductors, then the 21st may be the century of superconductors.”
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