Can imaginarity be broadcast via real operations?  

作　　者：Linshuai Zhang Nan Li 

机构地区：[1]Academy of Mathematics and Systems Science,University of Chinese Academy of Sciences,Beijing 100190,China [2]School of Mathematical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Communications in Theoretical Physics》2024年第11期66-75,共10页理论物理通讯（英文版）

基　　金：supported by the National Key R&D Program of China under Grant No.2020YFA0712700;the National Natural Science Foundation of China under Grant No.12341103;the Youth Innovation Promotion Association of CAS under Grant No.2020002。

摘　　要：Imaginarity has proven to be a valuable resource in various quantum information processing tasks.A natural question arises:can the imaginarity of quantum states be broadcast via real operations?In this work,we present explicit structures for nonreal states whose imaginarity can be broadcast and cloned.That is,for a nonreal state,its imaginarity can be cloned if and only if it is a direct sum of several maximally imaginary states under orthogonal transformation,and its imaginarity can be broadcast if and only if it is a direct sum of a real state and some nonreal qubit states which are mixtures of two orthogonal maximally imaginary states under orthogonal transformation.In particular,we show that for a nonreal pure state,its imaginarity cannot be broadcast unless it is a maximally imaginary state.Furthermore,we derive a trade-off relation on the imaginarity broadcasting of pure states in terms of the measure of irreversibility of quantum states concerning real operations and the geometric measure of imaginarity.In addition,we demonstrate that any faithful measure of imaginarity is not superadditive.

关 键 词：imaginarity BROADCASTING CLONING real operations 

分 类 号：O413[理学—理论物理]