However, the fundamental operations, such as single-qubit gates 14, 15, entangling gates 16– 20, and measurement 21 are known to populate non-computational levels, creating a demand for a reset protocol 22– 27 that can remove leakage population from these higher states without adversely impacting performance in a large-scale system. Superconducting transmon qubits are an appealing platform for the implementation of quantum error correction 4– 13. A friend has already encouraged me to try and take out time in order to post some things here.Īnother friend and I have already decided to team up on things we can write about together.Quantum error correction stabilizes logical states by operating on arrays of physical qubits in superpositions of their computational basis states 1– 3. It really allowed me to put things into context with regards to fault tolerant quantum computation.Īs a sidenote to my blog readers, I'll seriously try to be more frequent with my blogposts. Finally thank you to Daniel Gottesman for his talk on quantum error correction and fault tolerant quantum computation given at the Perimeter Institute for Theoretical Physics. I can safely say, I'm quite evangelical about teaching Quantum Mechanics using the unit circle and quantum information approach now. So thank you to Issac Chuang and Michael Nielson for their wonderful, 'Quantum Computation and Quantum Information' It truly is an amazing book! Thank you to Umesh Vazirani for his invaluable lecture notes which really helped me gain an understanding of the way concepts in quantum mechanics can be thought of in a more intuitive way using unit circles and what things like tensor products mean.

I think I should probably acknowledge the resources I used to construct this material. (control qubit flips the target qubit provided that the control qubit is 1) Your end result should be the same thing as the tensor product of |10> So expand out something like |11> as a tensor product and multiply that 4x1 matrix with the CNOT matrix. If you're interested in how it changes the tensor product of two kets or how you would show that a bit more explicitly, try doing the operation yourself. If anyones curious about it though, just search CNOT on google. Basically, powerpoint wasn't letting me add a 4x4 matrix so I had to write it on the board. As a note to anyone who's interested in the lecture slides, theres this one slide about the CNOT gate which is a bit interesting. Blogger isn't allowing me to post the lecture slides I made, so if anyone wants to see those, just take a look at my Linkedin profile(I should be able to post it there). Thanks again for all those who came to it! I hope all subsequent talks are equally as good, if not better!Īnyhow, I've listed the topics which were covered and I've attached the notes I made for the talk.

I volunteered to be its first speaker and I'm quite happy to say that the first talk was on the topic of quantum error correction. The UCL Physics Society has recently started an undergraduate physics colloquium. Sorry I haven't been very active on this blog, I'll certainly try to add things more frequently from now on.

Quantum error correction ramp