Efficient fidelity estimation:alternative derivation and related applications  

作　　者：Diego S Starke Marcos L W Basso Jonas Maziero 

机构地区：[1]Physics Department,Center for Natural and Exact Sciences,Federal University of Santa Maria,Roraima Avenue 1000,Santa Maria,RS,97105-900,Brazil [2]Center for Natural and Human Sciences,Federal University of ABC,Avenue of the States,Santo André,São Paulo,09210-580,Brazil

出　　处：《Communications in Theoretical Physics》2024年第9期16-20,共5页理论物理通讯（英文版）

摘　　要：In[Phys.Rev.A 107012427(2023)],Baldwin and Jones prove that Uhlmann–Jozsa’s fidelity between two quantum statesρandσ,i.e.,F(ρ,σ)=(Tr√√ρσ√ρ)^(2),can be written in a simplified form as F(ρ,σ)=(Tr√ρσ)^(2).In this article,we give an alternative proof of this result,using a function power series expansion and the properties of the trace function.Our approach not only reinforces the validity of the simplified expression but also facilitates the exploration of novel dissimilarity functions for quantum states and more complex trace functions of density operators.

关 键 词：Ulhmann–Jozsa fidelity Rényi entropy efficient fidelity estimation Chebyshev polynomials 

分 类 号：O413[理学—理论物理]