Average fidelity in n-qubit systems

被引：24

作者：

Cabrera, R. ^{[1
]}

Baylis, W. E. ^{[1
]}

机构：

[1] Univ Windsor, Dept Phys, Windsor, ON N9B 3P4, Canada

来源：

PHYSICS LETTERS A | 2007年 / 368卷 / 1-2期

基金：

加拿大自然科学与工程研究理事会;

关键词：

Nuclear magnetic resonance spectroscopy - Matrix algebra - Qubits - Linear transformations;

D O I：

10.1016/j.physleta.2007.03.068

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

This Letter generalizes the expression for the average fidelity of single qubits, as found by Bowdrey et al. [M.D. Bowdrey, D.K.L. Oi, A.J. Short, K. Banaszek, J.A. Jones, Phys. Lett. A 294 (2002) 2581, to the case of n qubits. We use a simple algebraic approach with basis elements for the density-matrix expansion expressed as Kronecker products of n Pauli spin matrices. An explicit integration over initial states is avoided by invoking the invariance of the state average under unitary transformations of the initial density matrix. The results have applications to measurements of quantum information, for example in ion-trap and NMR experiments. (c) 2007 Elsevier B.V. All rights reserved.

引用

页码：25 / 28

页数：4