By Benjamin Frederick Carlson
The world of computing could be getting much more interesting very soon. Mostly because the word “quantum” is involved and everyone sounds smarter when they use it.
The question we all have with quantum computers is “when do I get to buy one?” The truth is: not for a very, very long time–unless you’re Bill Gates, in which case you have enough money to buy one right now, install windows 10 on it and create a quantum superposition of blue and black screens of death.
Just kidding. Quantum computers aren’t anywhere near being able to run software, much less run even the simplest of calculations without extreme supervision. Quantum computers (as you might guess) work very differently from our regular “classical” Macs and PCs. I’m going to break down some of the differences and do my best to explain why quantum computers are so hard to deal with.
And if at the end of this article you are still just confused and scratching your head, just remember that the multi-verse theory states that in some universe you are the lead scientist in quantum computer development. 
Classic computers process information in 1s and 0s. For a “two bit” system, [00] could mean “no”, [10] could mean “yes”, [01] could mean “maybe” and [11] could mean “I’m sorry to bother you Batman, but Gotham needs you.” Each “1” or “0” is a “bit”, hence the two bit system. The more bits you have the greater and more complex information and computations a computer can process.
A two bit system [00] has four possible outcomes (22), a 3 bit system [000] has eight possible outcomes (23), a 4 bit system [0000] has sixteen possible outcomes (24) and etc… For extra credit, how many bits does your personal computer have and how many outcomes does that have?
Quantum computers ignore the normal rules for this classical way of processing information. Instead of a bit being a 1 or a 0, the bit is instead a superposition of 1 and 0. This means that it can be both 1 and 0 at the same time, which in turn implies that the computing power of a classical system is doubled if the system is replicated in a quantum computer.
Sounds cool, right? If they ever get it to work properly, it will be cool. But there are a lot of issues to deal with first. The most obvious perhaps is the environment. Global Warming is hurting our research in quantum computers. Okay that’s not true, but Al Gore would have had more of my attention if he had said something like that.
What I’m referring to is the environment the physical quantum computer is sitting in. In case you didn’t realize that quantum computers are not small, do a quick Google image search. Cool looking, but not small.
For the qubits to behave in a quantum mechanical sense, the physical environment has to be in a certain stable state. Heat and electromagnetic radiation are the primary causes in changing the physical environmental state. In order for a quantum computer to behave “quantumly”, so to speak, the computer must be cooled to just above absolute zero (around – 459 degrees F).
Any change in the temperature could interfere with the computer behaving accurately. Cooling the computer to such a low temperature is by no means an easy task, requiring the use of Helium 3: a very rare, non-radioactive isotope of Helium.
Then there are the problems of quantum entanglement. There is nothing worse than getting quantum decoherence in your computations because your qubits are entangled with each other. Entanglement refers to one of the spookiest and most interesting attributes of quantum mechanics. 
Remember how a qubit is a “superposition” of a 1 and 0? Well, what that means is that there is a mathematical “wave” function that represents the probability of the qubit being either a 1 or a 0. In other words, there is no actual value of the qubit until you try to take a measurement to see what it is. Any interaction from the environment, be it intentional or otherwise, “collapses” the wave function, forcing the qubit to be either a 1 or a 0. Interactions are labeled as “entanglement”.
The reason it’s known as “entanglement” is that it is incredibly difficult to completely isolate a system and thus hard to identify what exactly is interacting with the system and causing the wave function to collapse. So they say it is “entangled” with something.
Once the geniuses who are working in these fields understand how quantum mechanics work better I’m sure computers relying on such methods will surpass our present machines, but there is a lot of work that needs to be done.
In the meantime, I suggest you try to fit words like “quantum”, “entanglement”, “decoherence” and “collapsing wave function” into your day to day conversations. It will definitely up your ante with all those important online discussions you’re having from your mom’s basement.