User:Oriess/Evaluate an Article

Which article are you evaluating?
Bloch sphere

Why you have chosen this article to evaluate?
(Briefly explain why you chose it, why it matters, and what your preliminary impression of it was.)

I chose this article after having been introduced to Bloch notation in our Quantum Information and Computing class, and was curious to have a better understanding of the Bloch sphere, where it came from, and where it is applied. My preliminary impression of the Bloch sphere is that it is a 3-d representation of a space as indicated by a qubit. The poles of the sphere represent the |0> and |1> state corresponding toa spin-up or spin-down electron state.

Evaluate the article
(Compose a detailed evaluation of the article here, considering each of the key aspects listed above. Consider the guiding questions, and check out the examples of what a useful Wikipedia article evaluation looks like.)

I really enjoyed this article and gained a much better sense of this topic myself. However, in looking at this Wikipedia article corresponding to what we had in class, I do think that there are some pieces that could be developed further to give a more comprehensive look.

First, the leading section does a really good job of overviewing the topic, but one of the key aspects it mentions about the Bloch sphere is that there are pure states and mixed states dependent on if the point is on the sphere or in the sphere. One later heading is dedicated to Pure states, but there is none dedicated to mixed states. I think including this would be a really good addition to the article as its something I hadn't initially heard about and gives symmetry to the pure states section to show another part of Bloch sphere applications. I know that the density operator section somewhat covers this but I think a more in-depth explanation would be helpful.

Also, I noticed that one of the references used for this article, and specifically for the previous statement regarding mixed states is the Quantiki article for the Bloch sphere at https://www.quantiki.org/wiki/bloch-sphere. This statement already had a reference from Quantum Computation and Quantum Information, and I'm not sure that you need the Quantiki article as well for citation.

I noticed another reviewer on the talk page mentions that the pacing of the article goes a little too quickly, and I agree. They wrote that " In the first paragraph the "qubit" is introduced, while there is a section on the density operator at the end of the page." Focusing a bit more on those introductory pieces in a first section would be more valuable to then understanding the later operator sections.I think with all this talk of operators, it could be beneficial to the reader to have an understanding of what operators are and are not allowed in quantum information with regards to the Bloch sphere.

I do think that the images are good representations for the Bloch sphere, but the caption for the second picture could be more clear and concise.

Finally, the reference given at (5) is simply an explanation that should be included in the article isn't something I think should be kept in the References section.

Overall, I do think this is a really great article and I learned a lot!