When I hear the word “quantum”, I think of all the misconceptions and crazy ideas people associate with it in a lot of popular media. Physicists are great (and terrible) at coming up with names, and the word “quantum” is such an example of a word with a lot of baggage attached. Pair it with the word “computer”, however, and the misconceptions skyrocket, sometimes turning into full-blown hype. The reality (at the time of this writing) is much more modest: quantum computing presents an opportunity for thinking of computation differently, and the subsequent years will see how this plays out when theory meets experiment and engineering.

There’s a ton to talk about when it comes to quantum computing, but in this essay, I want to share with you something called a quantum error correcting code. It does what it says on the tin, and corrects errors that can accumulate during a computation. There are many such proposals, but one of the most popular is called the surface code, whose name will make sense as we dive into the details. The surface code is a proposal for how we can build a quantum computer that is robust to errors, but is only one step in the process. This essay is devoted to the surface code, how it works, and the challenges it faces when it comes to implementation.

In my final year of undergrad, I had a plan: go to the university near my house, begin my master’s degree, and eventually do a PhD. It was nice, simple, and straightforward. Not having a ton of people around me applying for graduate school, I wasn’t aware of how big a deal the choice of institution was, nor the fact that some people apply to ten or more schools (often for those looking to go in the US). In my case, I had someone at the local university agree to supervise me, and that was that.

Oh, and as a long-shot chance, I applied to a theoretical physics program in Waterloo, Ontario. I knew I would most certainly not get in, but it was free to apply so I wrote up my application quickly and sent it off, not thinking much about it.

Which is why I was very surprised to hear back from them at the beginning of March, asking for an interview.

If I’m having an argument, I tend to use phrases that include the word “you” or “they”. What I’m doing is projecting what I think a person is feeling into my own words. In essence, I’m taking what I think is important in their disagreement and only addressing that.

As a physicist, mathematics is the language I speak. It’s what I use to discuss physics, and I’m familiar with many of the tools that mathematicians learn. The tools range from the fields of calculus, probability, statistics, linear algebra, differential equations, graph theory, and many others. In particular, solving differential equations is like the bread and butter of physics, so I’m versed in this area. Knowing how to untangle the Schrödinger equation or the field equations in general relativity is a skill that physicists pick up during their education.