Quantum Memory 'World Record' Puts Scientists A Step Closer To Super-Fast Computers
Scientists have shattered the nerdiest kind of world record: They've managed to hold qubits, or quantum memory bits, in state for a whopping 39 minutes.
This has huge implications for the future of computing. It means we could eventually do away with binary code, the 0s and 1s that fuel your computer's processors. Instead, computers would harness the principles of quantum mechanics to process information faster than ever before.
Like Us on Facebook
In their article, published Friday in the journal Science, an international team of researchers led by Mike Thewalt of Simon Fraser University explained how they kept the quantum memory unchanged for more than 39 minutes at room temperature. Considering that the previous record was 25 seconds and that the subtlest external influence can ruin the whole experiment, the new record is practically forever.
To understand why this is so interesting, you have to understand the basics of quantum theory and quantum computing. We'll make it very simple.
Quantum physicists study subatomic matter (nuclei, photons and the like) and the way these things interact with energy. They quickly discovered that these particles can carry information in the same way a flashlight can carry information: It's either on or off. Similarly, a photon can either be polarized vertically or horizontally. Electron momentum can be measured as up or down. And so can nuclei. Scientists call these information carriers "quantum bits," or "qubits."
So far it just sounds like binary code, right? But it's not. The difference is difficult for us common folk to conceive of, yet it's the crux of the whole idea of quantum computing. Here it is: In addition to existing in one of two states, it can exist in both or multiple states at the same time. They call this ability "quantum parallelism," and the qubits' multi-state its "superposition."
In other words, the 0 and the 1 could be superimposed on the same qubit and interpreted at the same time by the computer's processor.
The possibilities of this kind of computing are vast. By developing new algorithms to take advantage of the increased capacity, quantum computers could be hundreds or thousands of times faster than conventional computers. A scientist at Amherst College recently raced a simple quantum computer against a regular computer and found that in some computations, the quantum computer was "thousands of times faster than anything I'm aware of," the researcher, Catherine McGeoch, said in a release. She cautioned, "At this point it's merely above average but shows a promising scaling trajectory."
The problem with qubits, though, has always been their fragility. McGeoch had to keep her qubits near absolute zero for her race. Remember, heat is just molecules in motion, and moving parts have a tendancy to knock qubits out of the state they're in.
That's part of what makes Thewalt's research so remarkable. According to the BBC, they prepared the phosphorous nuclei qubits at -452 degrees Fahrenheit (pretty much as cold as possible) and then raised it to room temperature. To their delight, they measured the unflinching state of the qubits for more than 39 minutes. "We further showed that a coherent spin superposition can be cycled from 4.2 kelvin [a little warmer than absolute zero, but colder than -452] to room temperature and back," the team reported.
If scientists figure out how to hold and measure qubits in a coherent position permanently, that's the key. Or one of the keys anyway.
"Having such robust, as well as long-lived, qubits could prove very helpful for anyone trying to build a quantum computer," co-author Stephanie Simmons of Oxford University told the BBC. "Thirty-nine minutes may not seem very long, but these lifetimes are many times longer than previous experiments. We've managed to identify a system that seems to have basically no noise."
© 2012 iScience Times All rights reserved. Do not reproduce without permission.