Genuine Counterfactual Communication with a Nanophotonic Processor

Abstract

In standard communication information is carried by particles or waves. Counterintuitively, in counterfactual communication particles and information can travel in opposite directions. The quantum Zeno effect allows Bob to transmit a message to Alice by encoding information in particles he never interacts with. The first suggested protocol not only required thousands of ideal optical components, but also resulted in a so-called "weak trace" of the particles having travelled from Bob to Alice, calling the scalability and counterfactuality of previous proposals and experiments into question. Here we overcome these challenges, implementing a new protocol in a programmable nanophotonic processor, based on reconfigurable silicon-on-insulator waveguides that operate at telecom wavelengths. This, together with our telecom single-photon source and highly-efficient superconducting nanowire single-photon detectors, provides a versatile and stable platform for a high-fidelity implementation of genuinely trace-free counterfactual communication, allowing us to actively tune the number of steps in the Zeno measurement, and achieve a bit error probability below 1%, with neither post-selection nor a weak trace. Our demonstration shows how our programmable nanophotonic processor could be applied to more complex counterfactual tasks and quantum information protocols.

arXiv comment6 pages, 4 figures

References in corpus (14)

• Detecting Single Infrared Photons with 93% System Efficiency
• Quantum Mechanical Interaction-Free Measurements
• Quantum transport simulations in a programmable nanophotonic processor
• Counterfactual Quantum Cryptography
• High-efficiency quantum interrogation measurements via the quantum Zeno effect
• Protocol for direct counterfactual quantum communication
• The past of a quantum particle
• Security of "Counterfactual Quantum Cryptography"
• Reducing multi-photon rates in pulsed down-conversion by temporal multiplexing
• Comment on "Protocol for Direct Counterfactual Quantum Communication" [arXiv:1206.2042]
• Modification of "Counterfactual communication protocols" which eliminates weak particle traces
• Quantum Counterfactual Communication Without a Weak Trace
• Evaluation of Counterfactuality in Counterfactual Communication Protocols
• Post-Selection and Counterfactual Communication

Cited by in corpus (13)

• Advances in silicon quantum photonics
• Universal programmable photonic architecture for quantum information processing
• Interaction-free, single-pixel quantum imaging with undetected photons
• How Quantum is Quantum Counterfactual Communication?
• Deterministic Teleportation and Universal Computation Without Particle Exchange
• Direct counterfactual quantum communication protocol beyond single photon source
• Counterfactual Logic Gates
• Coherent interaction-free detection of microwave pulses with a superconducting circuit
• Theory of coherent interaction-free detection of pulses
• $\mathcal{P}\mathcal{T}$-symmetric mapping of three states and its implementation on a cloud quantum processor
• Strongly non-quantitative classical information in quantum carriers
• Counterfactual Full-Duplex Communication
• Testing Single Photon Entanglement using Self-Referential Measurements