Bounds on quantum process fidelity from minimum required number of quantum state fidelity measurements

Bibliographic Details
Title: Bounds on quantum process fidelity from minimum required number of quantum state fidelity measurements
Authors: Fiurasek, Jaromir, Sedlak, Michal
Source: Phys. Rev. A 89, 012323 (2014)
Publication Year: 2014
Collection: Quantum Physics
Subject Terms: Quantum Physics
More Details: To certify that an experimentally implemented quantum transformation is a certain unitary operation U on a d-dimensional Hilbert space, it suffices to determine fidelities of output states for d+1 suitably chosen pure input states [Reich et al., Phys. Rev. A 88, 042309 (2013)]. The set of these d+1 probe states can consist of d orthogonal states that form a basis and one additional state which is a balanced superposition of all d basis states. Here we provide an analytical lower bound on quantum process fidelity for two-qubit quantum gates which results from the knowledge of average state fidelity for the basis states and the fidelity of the superposition state. We compare this bound with the Hofmann bound that is based on knowledge of average state fidelities for two mutually unbiased bases. We also discuss possible extension of our findings to N-qubit operations.
Comment: 7 pages, 2 figures
Document Type: Working Paper
DOI: 10.1103/PhysRevA.89.012323
Access URL: http://arxiv.org/abs/1401.5964
Accession Number: edsarx.1401.5964
Database: arXiv
More Details
DOI:10.1103/PhysRevA.89.012323