Beating the Classical Limits of Information Transmission using a Quantum Decoder

TL;DR

This paper demonstrates experimentally that quantum decoding can surpass classical limits in data transmission reliability over noisy channels using minimal channel uses and entanglement, with potential for larger systems.

Contribution

The authors experimentally show quantum advantage in data transmission over a noisy channel with minimal channel uses, using a photonic setup and entangling gates, extending to larger systems.

Findings

Quantum decoding improves reliability by over 20% for certain damping ranges.

Experimental setup uses only two channel uses per bit with a single entangling gate.

Simulations predict quantum advantage in larger systems with more channel uses.

Abstract

Encoding schemes and error-correcting codes are widely used in information technology to improve the reliability of data transmission over real-world communication channels. Quantum information protocols can further enhance the performance in data transmission by encoding a message in quantum states, however, most proposals to date have focused on the regime of a large number of uses of the noisy channel, which is unfeasible with current quantum technology. We experimentally demonstrate quantum enhanced communication over an amplitude damping noisy channel with only two uses of the channel per bit and a single entangling gate at the decoder. By simulating the channel using a photonic interferometric setup, we experimentally increase the reliability of transmitting a data bit by greater than 20% for a certain damping range over classically sending the message twice. We show how our methodology can be extended to larger systems by simulating the transmission of a single bit with up to eight uses of the channel and a two-bit message with three uses of the channel, predicting a quantum enhancement in all cases.