A Brand-New Concept of Superconductivity

A scientist from the Division of Quantum Condensed Issue Physics at the College of Tsukuba has developed a new concept of superconductivity. Based on the estimation of the ‘Berry connection,’ this version assists in discussing new experimental outcomes much better than the current concept. The work might enable future electrical grids to send out power without losses.

Superconductors are remarkable materials that may look plain at ambient problems, yet when cooled down to very low temperatures, permit electric presence to flow with no resistance. There are numerous obvious applications of superconductivity, such as lossless energy transmission, yet the physics underlying this process is still not clearly understood. The established way of considering the transition from regular to superconducting is called the Bardeen-Cooper-Schrieffer (BCS) theory. In this model, as long as thermal excitations are kept little sufficient, particles can develop “Cooper pairs,” which travel together and withstand scattering. Nevertheless, the BCS design does not appropriately explain all kinds of superconductors, limiting our ability to create even more robust superconducting products that work at area temperature.

A researcher from the University of Tsukuba has thought of a brand-new model for superconductivity that reveals the physical concepts better. Instead of focusing on the pairing of charged fragments, this brand-new concept uses the ‘Berry link’ mathematical tool. This value computes a turning off the room where electrons take a trip. “In the basic BCS concept, the beginning of superconductivity is electron pairing. In this theory, the supercurrent is identified as the dissipationless flow of the combined electrons, while single electrons still experience resistance,” Author Teacher Hiroyasu Koizumi states.

As an illustration, Josephson’s joints are formed when two superconductor layers are divided by a thin barrier of normal steel or an insulator. Although widely utilized in high-precision magnetic field detectors and quantum computers, Josephson junctions do not fit the inside BCS theory nicely. “In the brand-new theory, the electron pairing has to stabilize the Berry link, rather than being the source of superconductivity on its own, and the supercurrent is the flow of solitary and combined electrons generated due to the twisting of the area where electrons travel caused by the Berry link,” Professor Koizumi states. Therefore, this research might lead to innovations in the quantum computer as well as energy conservation.

Reference: Hiroyasu Koizumi, Superconductivity by Berry Connection from Many-body Wave Functions: Revisit to Andreev−Saint-James Reflection and Josephson Effect, Journal of Superconductivity and Novel Magnetism (2021). DOI: 10.1007/s10948-021-05905-y