Barrier-defying phenomenon in quantum realm

Even people without a background in science are familiar with Schrödinger's cat because of the sheer audacity of the idea: the cat in a box is both alive and dead at the same time until you actually observe it, at which time it is definitely dead.

- Kabir Firaque

Although he was one of the pioneers of quantum physics, Erwin Schrödinger's thought experiment showed that the ideas of quantum mechanics cannot easily be understood in terms of real-world objects.

Harnessing the strange properties of the quantum world for realworld use is the key to the future. Quantum computers work at speeds several orders of magnitude higher than that of classical computers, but building them for mass use remains a challenge. The key area being explored-super conducting electrical circuits - was, however, shown as far back as 1984-85, by physicists John Clarke (currently with University of California, Berkeley), Michel H Devoret (Yale University) and John M Martinis (UC Santa Barbara). Their work won them the Nobel Prize for Physics on Tuesday.

To understand the gap they helped bridge, consider a quantum particle, said to exist in multiple possible states simultaneously until an observation causes it to collapse into one definite state. Compare that with Schrödinger's cat: how can it be dead and alive at the same time? The three laureates demonstrated quantum properties on a scale somewhere in between that of a particle and a cat - a system large enough to be held in the hand. They carried out an experiment in UC Berkeley with a superconducting electrical system that "tunnelled" from one state into another, with measurements matching the predictions of quantum mechanics.