Three approaches for analyzing the counterfactuality of counterfactual protocols

Abstract

Counterfactual communication protocols are analysed using three approaches: a classical argument, the weak trace criterion, and the Fisher information criterion. It is argued that the classical analysis leads to contradiction and should therefore be abandoned. The weak trace and Fisher information criteria are shown to agree about the degree of counterfactuality of communication protocols involving postselection. It is argued that postselection is a necessary ingredient of counterfactual communication protocols. Coherent interaction experiments, as well as a recently introduced modification of counterfactual communication setups which eliminates the weak trace, are discussed.

18 pages, 13 figures, accepted to Phys. Rev. A

References in corpus (5)

• Protocol for direct counterfactual quantum communication
• Quantum Counterfactual Communication Without a Weak Trace
• Analysis of counterfactuality of counterfactual communication protocols
• Post-Selection and Counterfactual Communication
• Reply to "Comment on `Past of a quantum particle revisited' "

Cited by in corpus (4)

• Counterfactuality, back-action, and information gain in multi-path interferometers
• Exploring postselection-induced quantum phenomena with time-bidirectional state formalism
• Reply to "Counterfactual communication not achieved yet -- A Comment on Salih et al. (2022)"
• Theory of coherent interaction-free detection of pulses