Investigation of Strontium Ruthenate Disproves Novel Superconductivity Discovered in the 1990s

A lone measurement of results is not enough to prove scientific theories. Time and time again, sciences have been tested multiple times before any conclusive evidence can be gathered. Hence, a recent investigation on strontium ruthenate, a unique material that plays a key role in unconventional superconductivity, has just disproved a 1990s novel form of superconductivity experiment.

Superconductivity and the Coupled Spin of Two Particles

One of the greatest mysteries of solid-state physics is superconductivity, where some materials tend to lose electrical resistance at low temperatures. This phenomenon is yet to be fully understood by researchers. What is clear, on the other hand, is the known "Cooper pairs" that have a central role to play in superconductivity.

According to Science Alert, electrical currents in normal metals consist of individual electrons that would collide with each other and other metal atoms. But, superconductors have electrons move in pairs. Professor Andrew Pustogow, the lead author and researcher from the Institute of Solid State Physics, explains that the coupled spins of electrons dramatically change the situation of superconductivity.

He adds that when electrons are bound by the so-called Cooper pairs, they do not lose energy through the scattering of particles and move freely through the material without disturbance or resistance. The question now is, which conditions are conducive to the formation of Cooper pairs.

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New Measurements that Disprove the Novel Superconductivity of the 1990s

In a study published in the journal PNAS, entitled "Evidence for even parity unconventional superconductivity in Sr2RuO4," a team of international researchers headed by Pustogow studied the material for a different motive. However, in the process, the team realized that old measurements from a novel superconductivity experiment in the 1990s were incorrect.

The team was able to show that the exotic spin effects were a measurement artifact where the measured temperature did not match the actual temperature of the sample being studied. In fact, the sample that was studied back then was not superconducting at all.

With this information, the team decided to test the superconductivity of the material with the utmost precision. New results showed that the strontium ruthenate material is not a triplet superconductor. Rather, it had properties that correspond to what is known from cuprates.

On the other hand, for Pustogow, the results were anything but disappointing. He explains that the results bring out further understanding of superconductivity in high-temperature material, which is a step forward for science. Findings that strontium ruthenate showed were similar behavior to cuprates which means that researchers are not dealing with an exotic new phenomenon, but it also means that researchers now have a new material to investigate the phenomenon, according to an article by Phys.Org.

The team notes that the new measurements suggest that strontium ruthenate is prime new material for investigating the known phenomenons of superconductivity. Ultra-pure strontium ruthenates are more accurately suited for the experiments than other previously used materials. This way, researchers now have a cleaner test field than previously used cuprates.