The term “quantum” might falsely lead you to believe that a quantum computer is extremely small and something that you might lose in the seams of your pocket were you to slip it into your jeans. But in order for that to be true, you would need some absurdly large jeans, well beyond what “Big and Tall” might be able to supply you with.
Thursday I had the good fortune to be part of a group of about twenty Quest students and faculty (which included our president David, vice president Toran, Quest’s founder, and Quest’s new board member, Haig Farris, who we had to thank for making this trip possible) touring D-Wave Systems in Vancouver, BC, the primary producer of commercially available quantum computers in the world. Because they’ve been in the game for about fifteen years, they’re leagues beyond any other quantum computer researcher, something I’m painfully aware of while writing this blog post, as there are some photos I wasn’t able to take, let alone publicly broadcast across the internet.
This is the basic premise behind what sets quantum computers apart from the one you’re currently using to read this blog: quantum computers use what are known as qubits (quantum bits, pronounced kwibbits) as their most fundamental piece of information. Typical computers use transistors that are either in an on or off state, denoted by the familiar 1’s and 0’s of binary. Qubits use the motions of electrons around a path to denote 1’s and 0’s, but they can also do something normal computers can’t: exist in a superstate, where an electron is moving in both directions simultaneously. You might be familiar with this concept in the context of chemistry with electron clouds, where electrons are not in a single space spinning around the nucleus of an atom but instead occupying all spaces within the electron cloud simultaneously. It is that alleged superstate that allows the quantum computer to perform calculations at speeds unparalleled by any other computer technology we have today.
Unfortunately, no one (including D-Wave) is able to yet confirm with certainty that this is the mechanism quantum computers are taking advantage of. Because of the nature of this phenomenon, a huge amount of engineering effort is put into isolating the actual computing component (which is about the size of a Scrabble piece) from the rest of the universe. This includes light, acoustic vibrations, radio waves, toddlers, or anything else that might interfere with the computing processes (save for cosmic rays, which have a rare chance of occasionally bombarding the qubits). The qubits additionally require extremely low temperatures to take advantage of this quantum property of electrons. And when I say extremely low, I mean among the coldest in the universe, coming within a single degree of absolute zero, -273 degrees Celsius. This is done using superfluid helium (which is so cool it almost requires its own blog post), something that only becomes liquid with in 3 degrees Kelvin. The fact that the computer is operating at such an extremely undisturbed environment means that its difficult to distinguish if these are computers taking advantage of superpositions or if they are simply operating under the most ideal computing conditions with electrons moving in a frictionless system. What can be said, however, is that the macroscopic behavior of these computers match the quantum model of physics.
Even the exterior design of the machines embodies a self-aware sense of futuristic accomplishment, adorned with black paneling lettered with “D-Wave.” The lab itself felt as if it was paradoxically both the hub of the future of computing while alluding to the previous age when computers were the size of entire rooms. Simply being in the vicinity of such a beautiful combination of quantum physics and engineering prowess was a surreal experience, even if I lacked a holistic understanding of the mechanisms at work. Upon getting back to campus I returned to my physics 1 homework regarding the conservation of momentum, feeling suddenly like a child pushing colorfully painted pegs through holes.