Researchers create a conveyer belt for magnetic flux vortices in superconductors
If blown up in size, it would not have a chance in the car factory, but the microscopic conveyer belt built by Simon Bending’s team in the Department of Physics at the University of Bath and collaborators in Japan and the USA, could just be the next big thing for improving devices relying on the elusive properties of superconductors (Nature Materials, Advanced Online Publication March 12 2006). It’s not your standard rubber band on cylinders though – it moves in an erratic way, a quick jolt to the left, a smooth slide to the right. Who would want to be on such a thing?
Tiny swirls of electric currents, it seems. These so-called vortices are the closest things to ‘hurricanes’ for the superconducting researcher and engineer, and no less threatening. That’s because the zero resistance to current flow in even the best superconductors breaks down once vortices enter and start to move around. Their motion can also lead to unpredictable ‘noise’ if it takes place near the most sensitive regions of superconducting devices. Bending has now shown that it is possible to move vortices around inside a superconductor almost at will using his shaky conveyer belt. In this way they can either be removed entirely or at least left where they cause the least harm.
The asymmetry in its movement is the key to success, since it ensures that the vortices all move in one direction, even though the belt itself moves back and forth. The reason behind this is that the vortices can only follow along during the smooth slides to the right, and not during the jolts in the other direction. The conveyer belt thus acts in some sense as a rectifier, just like the diodes known from electronics.
The mind-boggling part is now that the conveyer belt is assembled out of a line of vortices itself, created and controlled by a time-varying magnetic field. As the researchers show, this way “bad” vortices can be completely removed out of targeted regions inside the superconductor, and the vortices induced to create the conveyer belt can be readily removed from the sample afterwards if need be.
Using this trick, superconducting devices, such as filters for telecommunications or ultra-sensitive magnetic field probes, could be improved by removing vortices - naturally caused by the earth’s magnetic field or man-made disturbances – from regions critical to device operation.
Bending’s team consisted of fellow researcher David Cole, and theoretical collaborators Sergey Savel’ev and Franco Nori from RIKEN (Japan) and the Universities of Michigan and Loughborough, as well as scientists from the Universities of Tokyo and Manchester.
Prof. Simon Bending | alfa
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...