Making Light Of Superconductors

Once upon a time, making a superconductor required extremely cold temperatures. Scientists understood why superconducting materials could move electrons without loss, but the super cold temperatures were a problem. Then in 1986, a high-temperature superconductor was found. High temperature, of course, is a relative term. The new material works when cooled to a frosty temperature, just not a few degrees off of absolute zero like a conventional superconductor. Since then, the race has been on to find a room-temperature superconductor that doesn’t require other exotic conditions, such as extreme pressure. Department of Energy scientists may have found a different path to get there: X-ray light.

The problem is that scientists don’t fully understand why these high-temperature superconductors work. To study the material, YBCO, scientists chill a sample to it superconducting state and then use a magnetic field to disrupt the superconductivity to study the material’s normal state. The new research has shown that a pulse of light can also disrupt the superconductivty, although the resulting state is unstable.

The research shows that charge density waves, which can serve as markers for superconductivity, occur when the samples are exposed to a magnetic field or to high-energy light pulses. While this is a far cry from creating room temperature superconductors, further study of the mechanism that allows light and magnetic fields to cause similar changes in the material could lead to a better understanding of the physics and maybe — one day — room-temperature superconductors.

Want to make your own YBCO? Go for it! Of course, you can already get room-temperature superconductors if you can stand the pressure.

Stacked Material Makes Kitchen Temperature Superconductors

Belgian, Italian, and Australian researchers are proposing that by stacking semiconductor sheets, they should be able to observe superconducting behavior at what is known as “kitchen temperature” or temperatures you could get in a household freezer. That’s not quite as good as room temperature, but it isn’t bad, either. The paper is a bit technical but there is a very accessible write-up at Sci-Tech Daily that gives a good explanation.

Superconductors show no loss but currently require very cold temperatures outside of a few special cases. The new material exploits the idea that an electron and a hole in a semiconducting material will have a strong attraction to each other and will form a pair known as an exciton. Excitons move in a superfluid state which should exhibit superconductivity regardless of the temperature. However, the attraction is so strong that in conventional materials, the excitons only exist for the briefest blip of time before they cancel each other out.

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Room Temperature Superconductor? Yes, But Not So Fast…

There’s good news and there’s bad news in what we’re about to tell you. The good news is that a team of physicists has found a blend of hydrogen, carbon, and sulfur that exhibit superconductivity at 59F. Exciting, right? The bad news is that it only works when being crushed between two diamonds at pressures approaching that of the Earth’s core. For perspective, the bottom of the Marianas trench is about 1,000 atmospheres, while the superconductor needs 2.6 million atmospheres of pressure.

Granted, 59F is a bit chilly, but it is easy to imagine cooling something down that much if you could harness superconductivity. We cool off CPUs all the time. However, unless there’s a breakthrough that allows the material to operate under at least reasonable pressures, this isn’t going to change much outside of a laboratory.

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Hackaday Links: January 5, 2012

Now make it life size

Here’s a scale model of the classic Playstation game Wipeout. It uses quantum levitation, superconductors, liquid nitrogen, and incredibly detailed models of the cars in Wipeout. They’re able control the speed and direction of the cars electronically. Somebody get on making one of these I can drive. Never mind, it’s totally fake, but here’s a choo-choo that does the same thing. Thanks for the link, [Ben].

Found a use for eight copies of Deep Impact

Where do you keep all your wire? [Paul] keeps his inside VHS tapes. It’s one of the most efficient ways of storing wire we’ve seen, just don’t touch those VHS copies of the original Star Wars trilogy.

There’s MAME machines for pinball?

MAME arcade machines are old hat, but we’ve never seen something to emulate pinball. The build uses two LCD monitors, a small computer and PinMAME. There’s videos in the build log; tell us if we’re stupid for wanting to build one. Thanks go to [Adrian] for sending this one in.

LEGO binary to decimal conversion

[Carl] is doing a few experiments to see if it’s possible to build a calculating machine out of LEGO. He managed to convert four bits of binary into decimal. We’ve seen a LEGO Antikythera mechanism but nothing on the order of an Analytical Engine or some Diamond Age rod logic. Keep it up, [Carl].

Lubs and Dubs that aren’t for dubstep

The folks at Toymaker Television posted a neat demo of heart rhythms emulated with a microprocessor. It cycles through normal sinus rhythm, atrial fibrillation, atrial flutter, and everything else that can go wrong with your heart. We know some nurses that would have loved this in school.