Timeline for Nielsen & Chuang Exercise 2.32: Show that the tensor product of two projectors is a projector
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 8, 2022 at 14:27 | answer | added | Lluvio Liu | timeline score: -1 | |
| Aug 29, 2020 at 19:16 | vote | accept | Attila Kun | ||
| Aug 29, 2020 at 6:58 | answer | added | DaftWullie | timeline score: 4 | |
| Aug 29, 2020 at 3:20 | comment | added | Attila Kun | Thanks, that answers my question. I tried proving $|i\rangle\!\langle i|\otimes\lvert j\rangle\!\langle j\rvert=\lvert i,j\rangle\!\langle i,j\rvert$ and managed to convince myself of its truth by expanding the terms into matrices/vectors and see what gets multiplied by what, but I'm wondering if there's a "nicer" way to do this. I tried looking at the definitions in Nielsen & Chuang (10th edition) page 73 but couldn't find anything useful, which is weird because the book usually introduces the necessary identities prior to the exercises. | |
| Aug 28, 2020 at 22:35 | comment | added | glS♦ | it's just a redefinition. More precisely you should write $|k\rangle=|i,j\rangle$. The only identity you are using is $|i\rangle\!\langle i|\otimes\lvert j\rangle\!\langle j\rvert=\lvert i,j\rangle\!\langle i,j\rvert$ | |
| Aug 28, 2020 at 22:33 | history | edited | glS♦ | CC BY-SA 4.0 |
deleted 19 characters in body
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| Aug 28, 2020 at 20:34 | history | asked | Attila Kun | CC BY-SA 4.0 |