An international team including researchers from the University of Wurzburg has succeeded in creating a special state of superconductivity. The discovery could advance the development of quantum computers.
The paper discussing the research has been published in Physics of nature titled Magnetically Tunable Supercurrent in Josephson Junctions Based on a Dilute Magnetic Topological Insulator.
Superconductors are materials which can conduct electricity without electrical resistance, making them the ideal base material for electronic components in magnetic resonance machines, magnetic levitation trains and even particle accelerators. However, conventional superconductors are easily disturbed by magnetism. An international group of researchers has succeeded in building a hybrid device consisting of a stable proximate superconductor enhanced by magnetism whose function can be specifically controlled.
Takes samples for millikelvin (-273 C) measurements. Image credit: Mandal/JMU, seitlich erweitert mit Firefly. University of Wurzburg. Click on the press release link for the larger view.
They combined the superconductor with a special semiconductor material known as a topological insulator. Topological insulators are materials that conduct electricity on their surface but not inside. This is due to its unique topological structure, i.e. the special arrangement of electrons, explained Professor Charles Gould, a physicist at the Institute of Topological Insulators at the University of Wurzburg (JMU). The exciting thing is that we can equip topological insulators with magnetic atoms so that they can be controlled by a magnet.
Superconductors and topological insulators were coupled to form a so-called Josephson junction, a connection between two superconductors separated by a thin layer of non-superconducting material. This allowed us to combine the properties of superconductivity and semiconductors, Gould said. So we combine the advantages of a superconductor with the controllability of the topological insulator. Using an external magnetic field, we can now precisely control the superconducting properties. This is a real breakthrough in quantum physics!
Superconductivity meets magnetism
The special combination creates an exotic state in which superconductivity and magnetism normally combine, these are opposite phenomena that rarely coexist. This is known as the proximity-induced Fulde-Ferrell-Larkin-Ovchinnikov (p-FFLO) state. The new superconductor with a control function could be important for practical applications, such as the development of quantum computers. Unlike conventional computers, quantum computers are not based on bits but on quantum bits (qubits), which can assume not just two, but several states simultaneously.
The problem is that quantum bits are currently very unstable because they are extremely sensitive to external influences, such as electric or magnetic fields, physicist Gould explained. Our discovery could help stabilize quantum bits so they can be used in quantum computers in the future.
International quantum research team
The experimental research was carried out by a team from the Chair of Experimental Physics III of Professor Laurens W. Molenkamp in Wrzburg. It was carried out in close collaboration with theoretical experts from the group of Professor F. Sebastian Bergeret from the Center for Physics of Materials (CFM) in San Sebastián, Spain, and Professor Teun M. Klapwijk from the Delft University of Technology in the Netherlands.
The international research group was funded by the Cluster of Excellence ct.qmat (Complexity and Topology in Quantum Materials), the German Research Foundation (DFG), the Free State of Bavaria, the Spanish State Research Agency (AEI), the European Research Group. the Horizon 2020 program and the ERC Advanced Grant program of the EU.
**
This answers some of the questions interested observers have had for years about the natural magnetic field around an energized superconductor. It’s no big surprise that an intrusive magnetic field wreaks havoc on a superconductor. However, it is also a surprise that the potential technology is already coming into focus.
One day, it seems the temperature problem will be the only major one left.
By Brian Westenhaus via New energy and fuel
More top reads from Oilprice.com:
#superconductor #pave #quantum #computers #OilPrice.com
Image Source : oilprice.com