Quantum parallelism in quantum information processing

作     者：Dugic, M Cirkovic, MM 

作者机构：Astron Observ YU-11160 Belgrade Serbia Yugoslavia Fac Sci Dept Phys Kragujevac Serbia Yugoslavia 

出 版 物：《INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS》 (国际理论物理学杂志)

年 卷 期：2002年第41卷第9期

页      面：1641-1649页

核心收录：

学科分类：07[理学] 070201[理学-理论物理] 0702[理学-物理学] 

主　　题：quantum operations fidelity nonideal measurement quantum parallelism 

摘      要：We investigate distinguishability (measured by fidelity) of the initial and the final state of a qubit, which is an object of the so-called nonideal quantum measurement of the first kind. We show that the fidelity of a nonideal measurement can be greater than the fidelity of the corresponding ideal measurement. This result is somewhat counterintuitive, and can be traced back to the quantum parallelism in quantum operations, in analogy with the quantum parallelism manifested in the quantum computing theory. In particular, as the quantum parallelism in quantum computing underlies efficient quantum algorithms, the quantum parallelism in quantum information theory underlies the classically unexpected increase of fidelity.