The first adjustable 鈥渋on trap鈥� could help scientists better understand the challenges of building practical quantum computers, researchers say.
Conventional ion traps confine atomic particles within a vacuum and an electric field generated by two fixed-position electrodes. The electronic states of these particles can be used to represent quantum bits of information. Unlike normal 鈥渂its鈥� of information, which are represented by distinguishable states, such as a binary 鈥�1鈥� or a 鈥�0鈥�, quantum information can exist in different states simultaneously.
This means computers that can process quantum information could perform mind-boggling computations instantaneously. However, maintaining quantum information is extremely difficult, and so building a sufficiently complex, practical quantum computer represents an enormous challenge.
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Louis Deslauriers at the University of Michigan, US, and Winfried Hensinger at the University of Sussex, UK, and colleagues, created the novel trap. It allows the distance between each electrode to be adjusted without losing the ion trapped in-between.
Scaling down
For the first time, this allowed them to measure precisely how down-scaling the trap affected the quantum state of the trapped ion. They found that reducing the size of the trap increased its temperature, thus boosting 鈥渄ecoherence鈥�, which could ultimately destroy quantum information.
It was still possible to shrink the trap down to 23 microns in diameter 鈥� the smallest ion trap ever made 鈥� without impairing its function. And, by cooling it to -120掳C, they were able to reduce the heating that threatened to destroy to the ion鈥檚 quantum properties.
Hensinger estimates that it should be possible to scale down an ion trap even further, to around 1 micron, providing it is cooled sufficiently. This could prove crucial as a practical quantum computer would require hundreds of thousands of such devices in order to perform useful calculations.
鈥淰ery clever鈥�
鈥淭he significance is quite big,鈥� Hensinger told New 杏吧原创. 鈥淭his adds an advantage to the field that other people can use.鈥� He adds that the cooling required should not make the construction of a working computer overly complicated.
鈥淚t鈥檚 very clever,鈥� says Daniel Segal, an ion trap researcher at Imperial College London in the UK, who agrees that the work could be very significant. 鈥淭his does a very systematic job of measuring something that is rather tedious, but is very important indeed,鈥� Segal says. 鈥淯p until this, the only evidence about how the heating rate scales with trap size came from different people鈥檚 heating rate measurements.鈥�
Hensinger believes ion traps hold the most promise for building quantum computers, but adds that much work remains to be done. 鈥淭here is still a very large challenge in bringing everything together,鈥� he warns.
