Superconductivity Seen in a New Light
March 31, 2016 | Université de GenèveEstimated reading time: 2 minutes
Superconducting materials have the characteristic of letting an electric current flow without resistance. The study of superconductors with a high critical temperature discovered in the 1980s remains a very attractive research subject for physicists. Indeed, many experimental observations still lack an adequate theoretical description. Researchers from the University of Geneva (UNIGE) in Switzerland and the Technical University Munich in Germany have managed to lift the veil on the electronic characteristics of high-temperature superconductors. Their research, published in Nature Communications, show that the electronic densities measured in these superconductors are a combination of two separate effects. As a result, they propose a new model that suggests the existence of two coexisting states rather than competing ones as was postulated for the past thirty years. A small revolution in the world of superconductivity.
A superconducting material is a material that, below a certain temperature, loses all electrical resistance (equal to zero). When immersed in a magnetic field, high-temperature superconductors (high-Tc) allow this field to penetrate in the form of filamentary regions, called vortices, in which the material is no longer superconducting. Each vortex is a whirl of electronic currents generating their own magnetic field and in which the electronic structure is different from the rest of the material.
Coexistence rather than competition
Some theoretical models describe high-Tc superconductors as a competition between two fundamental states, each developing its own spectral signature. The first is characterized by an ordered spatial arrangement of electrons. The second, corresponding to the superconducting phase, is characterized by electrons assembled in pairs.
«However, by measuring the density of electronic states with local tunneling spectroscopy, we discovered that the spectra that were attributed solely to the core of a vortex, where the material is not in the superconducting state, are also present elsewhere, that is to say in areas where the superconducting state exists. This implies that these spectroscopic signatures do not originate in the vortex cores and cannot be in competition with the superconducting state», explains Christoph Renner, professor in the Department of Quantum Matter Physics of the Faculty of Science at UNIGE. «This study therefore questions the view that these two states are in competition, as largely assumed until now. Instead, they turn out to be two coexisting states that together contribute to the measured spectra», professor Renner says. Indeed, physicists from UNIGE have shown, using theoretical simulation tools, that the experimental spectra can be reproduced perfectly by considering the superposition of the spectroscopic signature of a superconductor and this other electronic signature, brought to light through this new research.
This discovery is a breakthrough towards understanding the nature of the high temperature superconducting state. It puts some theoretical models based on the competition of the two states mentioned above in difficulty. It also sheds new light on the electronic nature of the vortex cores, which potentially has an impact on their dynamics. Mastery of this dynamics, and particularly of the anchoring of vortices that depend on their electronic nature, is critical for many applications, such as high field electromagnets.
Suggested Items
Siemens, Foxconn Team Up to Optimize Forward-thinking Manufacturing
05/16/2024 | FoxconnSiemens AG, a leading technology company, and Hon Hai Technology Group (Foxconn), the world’s largest electronics manufacturer, have signed a memorandum of understanding (MoU) to drive digital transformation and sustainability in smart manufacturing platforms.
IPC Releases May 2024 Global Sentiment of the Electronics Supply Chain Report
05/16/2024 | IPCSentiment among electronics manufacturers fell this month, after hitting a new high in April. Despite the decline, sentiment remains historically high according to IPC’s May Sentiment of the Global Electronics Manufacturing Supply Chain Report.
Sypris Reports Q1 2024 Results; Revenue Up 10%
05/15/2024 | Sypris Solutions Inc.The Company’s first quarter 2024 consolidated revenue increased 10.1% to $35.6 million compared with the prior-year quarter, representing the 11th quarter of double-digit year-over-year growth during the past 12 quarterly periods.
SMTC Strengthens Leadership for Future Growth: Ed Smith Promoted to Executive Chairman; Mike Buseman Joins as CEO
05/15/2024 | BUSINESS WIRESMTC Corporation, a leading North American provider of electronics manufacturing services, is pleased to announce the appointment of Mike Buseman as President & Chief Executive Officer, effective May 13, 2024.
Kimball Electronics Thailand Helps Save Lives by Hosting a Blood Drive
05/14/2024 | Kimball ElectronicsKimball Electronics Thailand employees took part in a blood donation event. The blood drive took place in the Rajapruek Building at Laem Chabang Industrial Estate Office.