How to check universality of quantum gates?

Autor: Sawicki, Adam, Mattioli, Lorenzo, Zimborás, Zoltán
Rok vydání: 2021
Předmět:
Zdroj: Phys. Rev. A 105, 052602, 2022 the title was changed to "Universality verification for a set of quantum gates"
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevA.105.052602
Popis: We provide two simple universality criteria. Our first criterion states that $\mathcal{S}\subset G_d:=U(d)$ is universal if and only if $\mathcal{S}$ forms a $\delta$-approximate $t(d)$-design, where $t(2)=6$ and $t(d)=4$ for $d\geq3$. Our second universality criterion says that $\mathcal{S}\subset G_d$ is universal if and only if the centralizer of $\mathcal{S}^{t(d),t(d)}=\{U^{\otimes t(d)}\otimes \bar{U}^{\otimes t(d)}|U\in \mathcal{S}\}$ is equal to the centralizer of $G_d^{t(d),t(d)}=\{U^{\otimes t(d)}\otimes \bar{U}^{\otimes t(d)}|U\in G_d\}$, where $t(2)=3$, and $t(d)=2$ for $d\geq 3$. The equality of the centralizers can be verified by comparing their dimensions.
Comment: 5 pages, quadratically improved centralizer condition for universality, some typos fixed and a discussion of the results added. The title of published version was changed to "Universality verification for a set of quantum gates"
Databáze: arXiv