Photonic implementation of quantum information masking

TL;DR

This paper extends the concept of quantum information masking to mixed states, demonstrating its feasibility with a photonic implementation that transfers and retrieves quantum information via bipartite correlations.

Contribution

It introduces a generalized definition of quantum masking for mixed states and experimentally demonstrates a photonic masking machine.

Findings

Maskable states are more abundant than previously thought.

Successful transfer and retrieval of quantum information in a photonic setup.

Potential applications in quantum secret sharing and fault-tolerant communication.

Abstract

Masking of quantum information spreads it over nonlocal correlations and hides it from the subsystems. It is known that no operation can simultaneously mask all pure states [Phys. Rev. Lett. 120, 230501 (2018)], so in what sense is quantum information masking useful? Here, we extend the definition of quantum information masking to general mixed states, and show that the resource of maskable quantum states are far more abundant than the no-go theorem seemingly suggests. Geometrically, the simultaneously maskable states lays on hyperdisks in the state hypersphere, and strictly contain the broadcastable states. We devise a photonic quantum information masking machine using time-correlated photons to experimentally investigate the properties of qubit masking, and demonstrate the transfer of quantum information into bipartite correlations and its faithful retrieval. The versatile masking machine has decent extensibility, and may be applicable to quantum secret sharing and fault-tolerant quantum communication. Our results provide some insights on the comprehension and potential application of quantum information masking.