A researcher at the University of Tsukuba introduces a new theoretical model for high temperature superconductivity, where electric current can flow with zero resistance, which can lead to extremely efficient energy production and transmission.
A scientist from the Division of Quantum Condensed Matter Physics at the University of Tsukuba has formulated a new theory of superconductivity. Based on the calculation of the “berry compound”, this model helps to explain new experimental results better than the current theory. The work may enable future electrical networks to transmit energy without loss.
Superconductors are fascinating materials that can look unremarkable in ambient conditions, but when cooled to very low temperatures, allow electric current to flow without resistance. There are several obvious applications of superconductivity, such as lossless energy transmission, but the physics underlying this process is still not clearly understood. The established way of thinking about the transition from normal to superconducting is called the Bardeen-Cooper-Schrieffer (BCS) theory. In this model, particles can form “Cooper pairs”
Now a scientist from the University of Tsukuba has come up with a new model for superconductivity that better reveals the physical principles. Instead of focusing on pairing charged particles, this new theory uses the mathematical tool called “Berry connection.” This value calculates a rotation of space where electrons move. “In the BCS standard theory, the origin of superconductivity is electron pairing. In this theory, the supercurrent is identified as the scatter-free current of the paired electrons, while individual electrons still experience resistance, ”says author Professor Hiroyasu Koizumi.
As an illustration, Josephson crosses are formed when two superconducting layers are separated by a thin barrier made of normal metal or an insulator. Although widely used in high-precision magnetic field detectors and quantum computers, Josephson crosses do not fit nicely into BCS theory either. In the new theory, the role of electron pairing is to stabilize the carrier connection as opposed to being the cause of superconductivity itself, and the supercurrent is the current of single and paired electrons generated due to the rotation of the space where electrons move caused by the Berry compound, ”says Professor Koizumi. Thus, this research can lead to advances in quantum computing as well as energy saving.
Reference: “Superconductivity of Carrying Connection from Many Body Wave Functions: Revisit to Andreev – Saint-James Reflection and Josephson Effect” by Hiroyasu Koizumi, July 5, 2021, Journal of Superconductivity and Novel Magnetism.
DOI: 10.1007 / s10948-021-05905-y