Question: ->Please explain me that how quantum physics would help evolving the integerated circuits of electronic devices?

Jack Miller answered on 22 Jun 2013:

The simple answer is “it already does”. The electrical devices that power computers — little switches called transistors — wouldn’t work if quantum mechanics wasn’t true. As transistors are really, really useful (and power everything from amplifiers to computers), it’s an area of the world that has been studied an awful lot, and modern-day consumer electronics just wouldn’t exist without the knowledge of quantum mechanics we have at the moment. I think, perhaps, this isn’t what you were asking however — as ordinary computers and ‘quantum computers’ are very different, even though ordinary computers in their present form wouldn’t exist without quantum mechanics!

Quantum computing is very different from ordinary computing, and I’m keen to let Dave tell you more about it. In short, in ‘ordinary’ computers you’ve got two ‘basic states’ for information: 1 and 0, which correspond to a pulse of electricity being somewhere, or not. In a quantum computer, you create an ‘entangled’ superposition of the two states where you don’t know if something is a given state until you decide to measure it. This gives you a lot more room to manouver, as the general state is a lots of one + b lots of 0, written as a|1>+b|0> — and a and b are, in general complex numbers. It’s therefore possible to do many different things at once in a really cool way, and as Dave is working on them at the moment, I think I’ll let him try to explain things!