What the heck is quantum computing? And should I care? I don’t know if you’ve noticed lately, but there is a new wave of computer technology being quietly developed in basement labs and secret company offices. I’m talking about“quantum computing”. Companies like Google, Microsoft and IBM, not to mention the U.S.government, have started investing heavily in the development of quantum computers in the last few years and news of their investments is slowly leaking out into mainstream media.So what is a quantum computer and why are all of the major powers that influence our lives interested in them?
Well the short answer is that they promise to be faster, safer,and better at solving certain kinds of problems than our trusty laptops. but that’s only one part of the quantum picture. First off lets figure out what it means for something to be “quantum”. Sometimes “quantum”is used interchangeably with “small” but that’s not accurate. Quantum things are happening on all length scales all the time–the distinction is that the likelihood that we notice these corrections on top of Newton’s “classical” physics decreases rapidly the bigger you get weird. At the quantum level, a particle can teleport, travel backwards in time, be “entangled” with a distant cousin, and a hypothetical cat in a box can be both alive and dead.
This apparently fantastical behavior is all possible because of science well, physics really and a little math.Most relevant to our quantum computing plot is the idea of “superposition” which transcends classical deterministic outcomes: alive or dead, heads or tails, 0 or 1, to describe these states as a distribution of probabilities: “the cat has a 70% probability of being alive” and as a funny outcome of the science we don’t get a fixed answer until we actually open the box and observe the cat, take a measurement, or otherwise ask the system for a specific output. A computer capable of exploiting this and other quantum properties, like entanglement, would not be constrained by a classical computer’s need to perform calculations sequentially because quantum bits would be capable of existing in a probability of many states and thus,be much better at tasks like simulating molecular bonds, performing rapid searches of complicated databases, or factoring large numbers very quickly.
These examples may seem silly or irrelevant until you learn, for instance, that factorization is prohibitively time-consuming for a classical computer, which is why it forms one common approach to data encryption. Now, quantum computers are looking pretty good, especially if you have an interest in National Security. So how close are we to a programmable quantum computer? Not that close. You’ll probably use one in your lifetime, but don’t run out to find one in the store just yet. Research in this area is happening at a rapid rate and has even resulted in the Nobel Prize for Physics in 2012, but scientists still have a long way to go. Challenges arise both from the difficulty in control and manipulation of quantum states, something that makes encoding quantum information difficult, as well as the vulnerability of that information to disturbance from the environment.
Nevertheless, scientists like those at Caltech’s Institute for Quantum Information and Matter,are working at the cutting edge of our current knowledge to make quantum computing a reality.And as for it’s potential, being able to simulate molecular interactions to create optimized materials on demand seems reason enough for Google, Microsoft and IBM to throw tons of money at quantum computing, But as one scientist recently reminded me: Who would have been able to foresee the impact of Facebook or the internet when classical computing was in development?What do you think? Will quantum computation change the world?