Quantum speed limit may put brakes on quantum computers
Posted by admin on 12th January 2018
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Over the past five decades, standard computer processors have gotten increasingly faster. In recent years, however, the limits to that technology have become clear: Chip components can only get so small, and be packed only so closely together, before they overlap or short-circuit. If companies are to continue building ever-faster computers, something will need to change.

One key hope for the future of increasingly fast computing is my own field, quantum physics. Quantum computers are expected to be much faster than anything the information age has developed so far. But my recent research has revealed that quantum computers will have limits of their own – and has suggested ways to figure out what those limits are.

The limits of understanding

To physicists, we humans live in what is called the “classical” world. Most people just call it “the world,” and have come to understand physics intuitively: Throwing a ball sends it up and then back down in a predictable arc, for instance.

Even in more complex situations, people tend to have an unconscious understanding of how things work. Most people largely grasp that a car works by burning gasoline in an internal combustion engine (or extracting stored electricity from a battery), to produce energy that is transferred through gears and axles to turn tires, which push against the road to move the car forward.

Under the laws of classical physics, there are theoretical limits to these processes. But they are unrealistically high: For instance, we know that a car can never go faster than the speed of light. And no matter how much fuel is on the planet, or how much roadway or how strong the construction methods, no car will get close to going even 10 percent of the speed of light.