Quantum Computing - The Very Edge of Science

A full-fledged quantum computer may sound like Sci-Fi but there are people (smart people by the way) that work to build it. "We're still 10 to 20 years away from a quantum computer," says Bells Labs' Steven Simon, as cited by the computer news site PCMag."But we're getting closer and closer." First of all, a quantum computer would use the principles of quantum physics to operate and achieve speeds that would make even today's super computers turn green with envy.

At Bell Labs there is a new quantum computing research project and they are hoping that a method to finally make this dream a reality is within their grasp. First proposed as a theory by the Nobel prize winner Richard Feynman, the quantum computer is for sure an idea that defies common sense. Modern day computers obey the same physical laws as we do, but a quantum computer will be outside those laws as it would operate with small particles like atoms.

Inside a classical computer, transistors are used to store bits of information, either 1 or 0. With a quantum computer, this is no longer true, as a quantum bit (qubit for short), is stored as the state of the spin of an atom's nucleus. The only problem is that a quantum computer could exist in multiple states at the same time. At any given time, the spin can be both up and down, so holding values of both 1 and 0. Putting two qubits together will result in the capacity of storing four values simultaneously (00, 01, 10, 11). This would make the quantum computer exponentially faster than any classical computer system. The problem with qubits is that when they are translated back into our classical worlds they collapse into a single state, so a quantum computer would lose most of its data.

Over the last decade or so, researchers proposed a number of technologies to get around this problem and some even built functional quantum computers on a very small scale. Bell's "topological quantum computing" is one of these methods and it seems that they are getting closer and closer to a viable prototype. In the simplest of terms, Bell researchers are tying quantum systems into knots. "In very exotic circumstances, such as very low temperature and high magnetic field, we're essentially grabbing onto the particles and moving them around each other, forming knots in what we call the space-time path," Simon explains. "If you can form the right knot, you can do the right quantum computation."