Scientists at Microsoft and their partners
around the world have spent the last decade exploring the exciting and utterly bizarre
place where computer science and quantum physics collide.
So where's that, exactly? Think about quantum computing like a subway
map with two train lines–the Quantum Physics Local and the Computer Science Express–coming
from different directions to meet at a central hub: Station Q.
On the map, the two lines meet and continue forward together, though no one knows exactly where they're headed. Thanks to brilliant minds from Newton to Einstein,
we have a pretty solid understanding of matter, motion, time, space, and how the universe
generally functions. But over the last hundred or so years, scientists looking closely at
life on an atomic and sub-atomic level started noticing some inconsistencies with traditional
physics. Questions and theories started piling up about how and why particles seem to behave
predictably on a large scale (like plants and birds and rocks and things), but on a
nanoscale it's, well, particles gone wild. It turns out that behaviors that seem impossible
to imagine on a human scale are downright pedestrian at a molecular level. Down there,
particles – little balls of solid matter – act like waves. Particles teleport from one place
to another, and can also become "entangled," making it impossible to separate them.
In a quantum state, particles can even achieve something we call superposition, where they
exist in multiple states simultaneously. You've ridden this line many times before.
You know that the laptop on your desk, the smartphone in your hand, and the tablet in
your bag all work with information in the form of bits. Bits, which can be either a
1 or a 0, are arranged in long, artful strings to get computers to do all sorts of things,
like sequence DNA or fling angry little birds at pig-built fortresses.
But classical computers have limits to their problem-solving prowess. There are some problems
so difficult that even if all the computers in the world worked on the problem in tandem
it would still take them a very long time to solve it.
So here's where things REALLY get interesting and where quantum computing could come in
handy. Quantum computers run on quantum bits, or qubits. Because of the mind-bending properties
of a quantum state, like superposition, a qubit can be a 1 or a 0 – or it can exist
as a 1 and a 0 at the same time. If one qubit, as a 1 and a 0, can do two calculations, then
two qubits can do four, four can do eight, and the computing power has the potential
to grow exponentially. With long strings of qubits performing computations,
problems that would take today's computers eons to solve could be tackled in the time
it takes to grab a cup of coffee. This could have wildest imagination-type applications
in fields such as machine learning and medicine, chemistry and cryptography, materials science
and engineering. And could allow humans to understand and control the very building blocks
of the universe.