New Superconducting Materials Discovered
Last year, three new exotic superconductor species were identified, demonstrating the various ways in which electrons can bond to create a frictionless quantum soup.
Recently, three discoveries of superconductivity in distinct materials have expanded the understanding of this phenomenon, which allows for the conduction of electricity without resistance. Two of these cases challenge established concepts, while the third completely questions the conventional theory of superconductivity. Ashvin Vishwanath, a physicist from Harvard who was not involved in the findings, remarked that this represents a very unusual form of superconductivity that many would have considered impossible.
Since its discovery by Heike Kamerlingh Onnes in 1911, superconductivity has intrigued scientists. The mystery lies in how, despite electrons repelling each other, they manage to come together and form pairs. This phenomenon is not only fascinating from a theoretical standpoint but has also led to significant practical applications, such as in magnetic resonance imaging machines and particle accelerators. Physicists aspire to develop materials that maintain superconductivity at room temperature, which could lead to revolutionary technological advances like lossless power grids and magnetically levitated vehicles.
Recent research in materials science has revealed that these new cases of superconductivity arise from devices made of flat layers of atoms. These structures exhibit unprecedented flexibility, allowing scientists to easily modify their electrical properties at the push of a button. This versatility has driven the search for superconductors in various directions, suggesting that different mechanisms may induce this phenomenon in dissimilar materials.
In 1957, John Bardeen, Leon Cooper, and John Robert Schrieffer clarified how paired electrons, known as Cooper pairs, form, which earned them the Nobel Prize in Physics in 1972. However, the superconductivities detected in cuprates in the 1980s posed a challenge to this theory, demonstrating that superconductors can exist at higher temperatures where atomic vibrations (phonons) are less relevant.
In 2018, Pablo Jarillo-Herrero made an important discovery by finding that twisting layers of graphene at a specific angle could achieve superconductivity. By studying two-dimensional materials, superconducting behaviors were being replicated much more efficiently than in traditional experiments that required the cultivation and testing of new crystals individually.
A significant breakthrough in this field occurred when a research team managed to create superconductivity in a molybdenum disulfide material. By altering the structure of the material and applying an electric field, they confirmed the presence of Cooper pairs in the composite material.
The exploration of new material configurations continues. For example, a group at Cornell discovered a form of superconductivity in a material system where electrons organize at a slow pace, thanks to the use of moiré patterns, which allow for more intense interactions.
Meanwhile, research on graphene continues to yield surprises. One graphene device has shown to produce a form of superconductivity that differs from those known to date, suggesting that there is still much to uncover in the field of superconductivity. This progress is in an intense exploration phase, where a complete understanding of the phenomenon could pave the way for new technologies.