Johns Hopkins University researchers and colleagues in China have unlocked some of the secrets of newly discovered iron-based high-temperature superconductors, research that could result in the design of better superconductors for use in industry, medicine, transportation and energy generation.
In an article published today in the journal Nature, the team, led by Chia-Ling Chien, the Jacob L. Hain Professor of Physics and director of the Material Research Science and Engineering Center at The Johns Hopkins University, offers insights into why the characteristics of a new family of iron-based superconductors reveal the need for fresh theoretical models which could, they say, pave the way for the development of superconductors that can operate at room temperature.
“It appears to us that the new iron-based superconductors disclose a new physics, contain new mysteries and may start us along an uncharted pathway to room temperature superconductivity,” said Chien, who teamed up on the research with Tingyong Chen and Zlatko Tesanovic, both of Johns Hopkins, and X.H. Chen and R.H. Liu of the Hefei National Laboratory for Physical Science at Microscale and Department of Physics, University of Science and Technology of China in Anhui, China.
Superconductors are materials that can carry electrical current without friction and as a result, don’t waste electrical energy generating heat. (Imagine your laptop computer or PC not getting warm when it is turned on.) This means that an electrical current can flow in a loop of superconducting wire forever without a power source. Today, superconductors are used in hospital MRI machines, as filters in cell phone base stations and in high-speed magnetic levitating trains. Unfortunately, most of today’s superconducting materials can only function and operate at extremely low temperatures, which means that they must be paired with expensive supercooling equipment. This presents researchers with a grand challenge: to find superconducting material that can operate at more “normal” temperatures.
“If superconductors could exist at room temperatures, the world energy crisis would be solved,” Chen said.
Chen explains that though all metals contain mobile electrons which conduct electricity, a metal becomes a superconductor only when two electrons with opposite “spins” are paired. The superconductor energy “gap,” which is the amount of energy that would be needed to break the bond between two electrons forming such a pair to release them from one another, determines the robustness or strength of the superconducting state. This energy gap is highest at low temperatures, but vanishes at the temperatures at which superconductivity ceases to exist.
“This gap -- its structure and temperature dependence -- reveal the ‘soul’ of the superconductor, and this is what was measured in our experiment,” Chien said.
The team measured this gap and its temperature variation, revealing that the pairing mechanism in iron-based superconductors is different from the one in more traditional, copper-based, high-temperature superconductors. To the researchers’ surprise, their results were incompatible with some of the newly proposed theories in this mushrooming field.
“In the face of this discovery, it is clear that we need to reexamine the old and invent some new theoretical models,” Tesanovic said. “I predict that these new, iron-based superconductors will keep us physicists busy for a long, long while.”
This research was supported by the U.S. National Science Foundation and the Natural Science Foundation of China.
Lisa De Nike | newswise
Linear potentiometer LRW2/3 - Maximum precision with many measuring points
17.05.2017 | WayCon Positionsmesstechnik GmbH
First flat lens for immersion microscope provides alternative to centuries-old technique
17.05.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy