Physicist Milan Allan and his team at Leiden University have discovered an obvious insulation phenomenon in high-temperature superconductor materials. Although in theory the charge should flow without resistance, they mentioned the trap charge. This discovery may provide a missing piece to a major mystery of physics today—high-temperature superconductivity. The findings are published in the journal NaturePhysics.
This material can have both insulation and conductivity. As an insulator, extra electrons are trapped. Therefore, no current flows on the insulator. As a conductor, the extra electrons flow freely. The more conductive the material, the faster the electrons flow.
So, physicist Milan Allan and his team at Leiden University were surprised to find that trapped charges exist in a superconducting material. The trap charge has always been considered a signal of the insulator. A team of theoretical physicists Jan Zaanen and Milan Allan at the University of Leiden found that this phenomenon may unlock long-standing secrets about charge transport in copper salt materials. This incompletely understood copper salt material has no resistance at relatively high temperatures, so it is called a high-temperature superconductor. The mechanism of this phenomenon is still a big mystery of physics today.
PhD students Koen Bastiaans and Tjerk Benschop and postdoc DooheeCho spent two years building a new microscope. The average signal is measured on the basis of fluctuations in the signal-often called noise. These fluctuations indicate the presence of electron trapping in the insulating layer of the layered material under study. The materials were developed by scientists at the University of Amsterdam. Microscopes record noise at the atomic scale, which is essential for discovering noise phenomena. Bastiaans says "noise is concentrated in only a few local areas, as if some atoms are noisier than others. Our microscopes can help us understand not only these materials, but also these noisy noises."