The impending revolution of low-power quantum computers

The impending revolution of low-power quantum computers
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By 2017, quantum physics will help reduce the energy consumption of our computers and cellular phones by up to a factor of 100. For research and industry, the power consumption of transistors is a key issue. The next revolution will likely come from tunnel-FET, a technology that takes advantage of a phenomenon referred to as "quantum tunneling."

At the EPFL, but also in the laboratories of IBM Zurich and the CEA-Leti in France, research is well underway. As part of a special issue of Nature devoted to , Adrian Ionescu, an EPFL , has written an article on the topic.

Today's computers have no less than a billion transistors in the CPU alone. These small switches that turn on and off provide the famous binary instructions, the 0s and 1s that let us send emails, watch videos, move the mouse pointer… and much more. The technology used in today's transistors is called "field effect;" whereby voltage induces an electron channel that activates the transistor. But field effect technology is approaching its limits, particularly in terms of .

Tunnel-FET technology is based on a fundamentally different principle. In the transistor, two chambers are separated by an energy barrier. In the first, a horde of electrons awaits while the transistor is deactivated. When voltage is applied, they cross the energy barrier and move into the second chamber, activating the transistor in so doing.

In the past, the tunnel effect was known to disrupt the operation of transistors. According to quantum theory, some electrons cross the barrier, even if they apparently don't have enough energy to do so. By reducing the width of this barrier, it becomes possible to amplify and take advantage of the quantum effect – the energy needed for the electrons to cross the barrier is drastically reduced, as is power consumption in standby mode.

"By replacing the principle of the conventional field effect transistor by the tunnel effect, one can reduce the voltage of from 1 volt to 0.2 volts," explains Ionescu. In practical terms, this decrease in electrical tension will reduce power consumption by up to a factor of 100. The new generation microchips will combine conventional and tunnel-FET technology. "The current prototypes by IBM and the CEA-Leti have been developed in a pre-industrial setting. We can reasonably expect to see mass production by around 2017."

For Ionescu, who heads the Guardian Angels project (a project vetted for a billion Euro grant from the EU), tunnel-FET technology is without a doubt the next big technological leap in the field of microprocessors. "In the Guardian Angels project, one of our objectives is to find solutions to reduce the power consumption of processors. Tunnel-FET is the next revolution that will help us achieve this goal." The aim: design ultra-miniaturized, zero-power electronic personal assistants. Tunnel-FET technology is one of the first major stages in the project's roadmap. IBM and the CEA-Leti are also partners in the project.

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More information: Tunnel field-effect transistors as energy-efficient electronic switches, Nature, … ull/nature10679.html
Journal information: Nature

Provided by Ecole Polytechnique Federale de Lausanne
Citation: The impending revolution of low-power quantum computers (2011, November 22) retrieved 19 July 2019 from
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Nov 22, 2011
These aren't quantum computers. These are components for classical computers exploiting quantum effects.

Nov 22, 2011
lol, there was just an article about photonic computers. It also said something along the lines of "the coming revolution". I keep hearing about the revolution, but it never seems to make it off the drawing board.

Nov 23, 2011
Is this new? Seems I have heard this before.

...hold on a sec...

...Ah, I remembered correctly...just checked my university books from 15 years ago: Tunnel-FET was part of the curriculum on semiconductor components back then.

Nov 23, 2011
These aren't quantum computers. These are components for classical computers exploiting quantum effects.
In addition, the uncertainty principle is valid for both. The same integration density, noise/signal ratio and speed limits apply for both classical, both "quantum" computers. So you cannot actually get any gain in computational power, until the reliability and stability of quantum computers at given temperature would remain the same like those of classical computers. It just means, the quantum computers are merely a hype and salary generators for researchers involved.

Nov 23, 2011
I could use a mobile phone that needs recharging only a few times a year. Oh, I remember the days when I could go for a week on a single charge. But now my smart-phone is lucky to last till I get home from work.

I will, however, not see that day. Ever. Before that someone invents, advertises, and deploys some technology that recharges mobile phones "on the run". (This might be cars, buses, trains, mall aisles, the pub, the stadium, work and home.) Once that is ubiquitous, phone batteries will be that much smaller "because we want our phones to be light in the pocket".

Just don't stray out of town, or you're stranded in an hour. But then, of course, you'd have another phone for Rural Expeditions, just like everybody today drives an SUV, which supposedly is for the countryside, 4-wheel drive and all.

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