Tag: superconductor

Etch-a-Sketch method used for precision superconductors

Researchers have developed a new method to create superconducting circuits, drawing them out Etch-a-Sketch style.

A group of scientists at the UCL London Centre for Nanotechnology and the Physics Department of Sapienza University of Rome were able manipulate superconducting materials on a minute scale – opening possibilities for a new generation of electronic devices.

Superconducting materials offer exciting possibilities for electronics, operating in a special state where electricity is conducted without any resistance whatsoever.  This means that there is zero wasted energy.

While this usually occurs at temperatures nearer to absolute zero, developments have brought about ‘high’ temperature superconductors.  The researchers created such a superconductor by combining oxygen, copper, and rare earth material lanthanum.

An X-ray beam is then used to draw two dimensional shapes in the material like a pen by manipulating the oxygen atoms. 

This means that it is possible to write superconductors in minute detail, less than the width of a human hair. 

Furthermore it means that chemicals are no longer needed in any such process, with the etch-a-sketch movement of oxygen atoms sufficient for the fabrication process.

According to professor Aeppli at the LCN, this means that there are “exciting new possibilities” for electronics devices, particularly with the re-writing of superconductor logic circuits.

Aeppli also reckons it will help solve the age old ‘travelling salesman problem’.  

Scientist wants to solve energy crisis with Saharan sand

An initiative by universities in Japan and Algeria aims to provide half of the world’s energy before 2050 by “breeding” solar panel plants in the Sahara desert.

The idea behind it all is to combine the two most abundant things you would find in the Sahara desert, namely sun and sand, by firstly building a handful of silicon manufacturing plants which could then use the plentiful sand to create high-quality silicon used in solar panels. 

The energy generated by the solar panels would then be used to build the next generation of plants and solar panel.  These would then repeat the cycle by “breeding” even more cute little baby silicon power plants, and so on and so forth.

Although no one has actually attempted to make silicon from the rough sands of the Sahara, Hidemi Koinuma from the University of Tokyo believes that it is merely common-sense.

“From the viewpoints of quality, quantity and chemistry, Sahara sand is hard to beat for use as silicon for solar cells,” he says.

According to the New Scientist this is not the first attempt to turn the Sahara into a giant solar panel, with the Desertec Foundation also planning to pick up around 15 percent of Europe’s ‘leccy bill, though is the first initiative to use the surrounding sand to sustain development.

However Desertec believes that the idea may be a tad difficult to pull off in reality, although it is a step in the right direction.  The ‘high-temperature’ superconductors that would be needed to distribute the power as a direct current could cause a problem in fact usually function at the not very high temperature of  -240c, so will need to spend considerable energy to cool them.

“There is not really a need for superconductors. By using high-voltage direct current transmission lines it is possible to transport clean power from the deserts over long distances to centres of consumption,” says a Desertec spokesman. “Transmission losses are fairly low – around 3 per cent per 1000 kilometres. Unlike superconductors, there is no need for cooling, while power transmission costs are just 1¢ to 2¢ per kilowatt-hour.”

Koinuma however believes that there is potential for linking the desert based power stations to a network of supercooled high-voltage DC grid for transporting electricity 500 km or more.

“Even if we need to cool the grid line with liquid nitrogen, the system could be cost-competitive,” he claims.

Japanese firms to start making superconducting wire

Sumitomo Electric Industries and SWCC Showa Holdings will steal a march on foreign competitors by beginning production of superconducting wire to be used in electric car motors and smart grids.

It is hoped that by switching from standard copper wire before rival companies from the US and South Korea the two Japanese firms will gain an edge in the global market.

The use of superconducting wire will mean significant reduction in power loss by conserving electricity and improving mechanical performance, which can mean in the region of 20 percent energy savings for a large factory.  For the motors of electric vehicles the wire will be able to increase driving range by around 25 percent, which could assist in the take-up of environmentally friendly transportation.

Sumitomo Electric seeks to become the world’s largest superconductor wire manufacturer next year by increasing capacity next year by double to 1,000km at its Osaka plant.  Its increased output of bismuth-based wire will see it overtaking US firm American Superconductor Corp.  The wire costs twice as much as copper, though volume production will lower this cost by 30 percent.

One of Sumitomo Electric’s customers will be Tokyo Electric Power, which will be purchasing superconducting wire for installation at a transformer station in Yokohama, making it the first utility in Japan to use the wire in commercial power transmission.  Further orders have been received including one for 40km from China, and an order for more than 100km from an unspecified buyer, according to Nikkei (subscription needed)

SWCC Showa, meanwhile, will begin the mass production of an yttrium-based superconducting wire this year for use in high-output motors, with needed plant investments to total $12 million.

Overall the domestic market for superconducting wire used in power cables will measure about $589 million in 2030, according to the New Energy and Industrial Technology Development Organization.  It is also expected that US will increase demand as it replaces its aging power grid infrastructure.

Split personality of superconductor material offers possibilities for quantum computing

A superconductor has been observed which has two electronic identities at once offering a revolutionary way for next-generation electronics to store and process information, with particular relevance to quantum computers.

The new material is a crystal that has been described as being part superconductor and part metal, named a “topological superconductor” by scientists at Princeton University.  When at very low temperatures the crystal’s interior conducts electricity with no resistance as a normal superconductor would.  However the surface is metallic, and therefore has resistance to any current carried.

Usually materials are either in one category or another, be it metal, insulator or superconductor and so will consistently provide the same amount of resistance, according to M. Zahid Hasan, an associate professor of physics at Princeton.

“The known states of electronic matter are insulators, metals, magnets, semiconductors and superconductors, and each of them has brought us new technology. Topological superconductors are superconducting everywhere but on the surface, where they are metallic; this leads to many possibilities for applications.”

Princeton says that one of the most exciting potential uses for the material would be in energy-efficient quantum computers that would have the ability to identify errors in calculation as they occur and resist them during processing.

Fundamental to being able to do this is manipulating Majorana fermions, the catch being that they have been predicted over 70 years ago, though not actually observed.  It is thought that the dual electronic personality of a superconductor with different surface properties may allow electrons on the surface to become Majorana fermions, according to Hasan. 

According to physicist Charles Kane of the University of Pennsylvania, if a topological superconductor were to be placed in contact with a topological insulator, some of the electrons at the interface could become long-sought Majorana fermions if the composite material were placed into a very strong magnetic field.

This is a process that could take many years to refine however, with Hasan adding that “it takes time to go from new physics to new technology — usually 20 to 30 years, as was the case with semiconductors.”

According to L. Andrew Way the split personality of such an unusual superconductor lends itself well to quantum computing.

“These highly unusual superconductors are the most ideal nurseries to create and manipulate Majorana fermions, which could be used to do quantum computing in a fault-resistant way.  And because the particles would exist on a superconductor, it could be possible to manipulate them in low power-consumption devices that are not only ‘green,’ but also immune to the overheating problems that befall current silicon-based electronics,” said Way.