Quantum and classical fidelities for Gaussian states

Abstract

We examine the physical significance of fidelity as a measure of similarity for Gaussian states, by drawing a comparison with its classical counterpart. We find that the relationship between these classical and quantum fidelities is not straightforward, and in general does not seem to provide insight into the physical significance of quantum fidelity. To avoid this ambiguity we propose that the efficacy of quantum information protocols be characterized by determining their transfer function and then calculating the fidelity achievable for a hypothetical pure reference input state.

9 pages, 5 figures, to be published in J. Opt. Soc. Am. B special issue on Optical Quantum Information Science

References in corpus (5)

• Distance measures to compare real and ideal quantum processes
• Tripartite Quantum State Sharing
• Complementary classical fidelities as an efficient criterion for the evaluation of experimentally realized quantum operations
• Operationally Invariant Measure of the Distance between Quantum States by Complementary Measurements
• Classical phase-space descriptions of continuous-variable teleportation

Cited by in corpus (7)

• Unconditional Room Temperature Quantum Memory
• Quantum fidelity for Gaussian states describing the evolution of open systems
• Effect of the heralding detector properties on the conditional generation of single-photon states
• Estimating space-time parameters with a quantum probe in a lossy environment
• Revisiting maximal average fidelity of teleportation
• Coherence Protection of Electron Spin in Earth-field Range by All-optical Dynamic Decoupling
• Classical analogs of the covariance matrix, purity, linear entropy, and von Neumann entropy