Quantum computers may be one step closer to reality, thanks to a new breakthrough in qubit technology.
Quantum bits (qubits) can exist in multiple states simultaneously. They replace the simple on-off bits of contemporary computers with on, off, and "something in between." On the subatomic level, particles exhibit different states and can even exist in more than one form at the same time. It is this odd superposition that provides the underlying power of quantum computers.
These theoretical devices are extremely fragile, and prone to failure. Researchers at the University of California Santa Barbara have created a stable five qubit array for the first time ever, achieving an accuracy rate of 99 percent.
"Quantum hardware is very, very unreliable compared to classical hardware. Even the best state-of-the-art hardware is unreliable. Our paper shows that for the first time reliability has been reached," Austin Fowler, a researcher on the study, said in a press release.
The physicists created a series of qubits, shaped like a cross, that they term "Xmons." Five of these sets were placed next to each other. The tiny arrangement was cooled down to the point where magnetic fields and electrical resistance disappeared. This provided each qubit the ability to interact with its nearest neighbors.
Qubits have an intrinsic rate of mistakes, caused by the bizarre laws of subatomic physics. To become viable as real-world processors, this error must be reduced below a certain level. Error correction is needed in processors to reduce the possibility of delivering erroneous data. The 99 percent reliability rate in the new systems is high enough for effective error correction.
"If you want to build a quantum computer, you need a two-dimensional array of such qubits, and the error rate should be below 1 percent," said Fowler. "If we can get... in the area of... 1 in 1,000 for all our gates - our qubits could become commercially viable."
Future processors may feature qubits arranged like a checkerboard pattern, with "black" squares checking for errors from processing performed by "white" squares.
Quantum computers could lead to a whole new generation of computing devices. These systems could perform tasks millions of times faster than today's technology. This could lead to advances in weather and climate predictions. Medical research could be accelerated by the new generation of computing systems.
Pete Worden of the Ames Research Institute believes quantum computers may even be able to uncover fundamental equations of universal physics.
Development of the stable five-qubit system was profiled in the journal Nature.
