Quantum Computer with Schrodinger's Cat included.
Posted on 07/23/2006 5:30:08 PM PDT by annie laurie
Physicists of the University of Bonn have taken one more important hurdle on the path to what is known as a quantum computer: by using 'laser tweezers' they have succeeded in sorting up to seven atoms and lining them up. The researchers filmed this process and report on their breakthrough in the next issue of the prestigious journal Nature (13th July 2006).
In the experiment the research team headed by Dr. Arno Rauschenbeutel and Professor Dieter Meschede decelerated several caesium atoms for a period of several seconds so that they were hardly moving, then loaded them onto a 'conveyor belt' consisting of lasers. This conveyor belt is made up of a standing light wave composed of many peaks and troughs – possibly comparable to a piece of corrugated iron. 'Unfortunately it cannot be predicted which trough precisely the atoms will land in,' Arno Rauschenbeutel explains. 'It's rather like pouring several eggs from a big dish into an egg carton – which section each egg rolls into is a matter of chance.'
However, anyone wishing to calculate with atoms must be able to place them exactly. 'All the atoms on the conveyor belt have to have the same distance from each other,' is how Arno Rauschenbeutel sketches the challenge. 'Only then can we get them to interact in a controlled way in what is called a quantum gate.' By lining up gate operations like these it would already be possible to carry out simple quantum calculations.
The Bonn physicists therefore subsequently 'sorted' the atoms in their experiment on the conveyor belt. They did this by first taking a photo to record their positions. They next set the conveyor belt moving – and with it the caesium atoms 'trapped' in the troughs. In this way they transported the wrongly placed atoms to their 'laser tweezers' – this is basically nothing more than another conveyor belt consisting of laser beams which is oriented orthogonally to the first conveyor belt. 'When we set the tweezers' light wave in motion, we can lift the wrongly placed atoms off the conveyor belt,' Arno Rauschenbeutel explains. 'Then we move the conveyor belt to the desired position and simply pop the atom back in.'
The film shows how well this works: the tweezers select two atoms consecutively from the belt and put them back on again in such a way that they are exactly the same distance from each other and from a third atom. 'Sorting seven atoms in this way takes us about two seconds,' Dr. Rauschenbeutel says.
The next aim of the Bonn physicists is to construct a quantum gate. For this purpose they want to 'write' quantum information onto two caesium atoms and then place them between two tiny mirrors. The intention is that they should interact there with each other, i.e. exchange information by emitting and absorbing fluorescent light. If this is successful, it will be the next milestone for the Bonn researchers on their way to the quantum computer.
Citation: An atom-sorting machine. Yevhen Miroshnychenko, Wolfgang Alt, Igor Dotsenko, Leonid Fцrster, Mkrtych Khudaverdyan, Dieter Meschede, Dominik Schrader, Arno Rauschenbeutel. Nature, 13th July 2006 (Vol. 442, No 7099)
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Quantum Computer with Schrodinger's Cat included.
LOL
Caption: "Would you people just open the dang box already and get it over with?" ;-)
"Yes, we've designed the world's smallest computer. It is a quantum computer. That's the good news. The bad news is that it needs a gym's worth of equipment to set it up, initialize it, keep it cool, and a super computer to program it."
Perhaps rather than trying to precicely position them on a single conveyor, use two conveyors as a binary system; either a conveyor has atoms or it doesn't. In so doing, you may not need to worry about precise positioning within a single conveyor.
No difference from the computer of ~40 years ago.
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...even though that cat isn't grey
I wonder what eigenvalue it will fetch on eBay?
What will a Quantum Computer allow us/anyone to do that we cannot do now?
I always thought quantum computing was being able to do what we do now..but, all at the same time.
Virtual Reality
Spooky stuff. I think it produces results that don't exist until you look at them. But it's said to theoretically be able to crack strong encryption at a single bound. Faster than a speeding bullet, and all that stuff.
So it's really the traditional advancement of "more, better, faster, smaller" etc?
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