Qubit Advantage Persists Even With Noise In Communication

Researchers Partha Patra, Sumit Mukherjee, and A. K. Pan have demonstrated a qubit can outperform a classical bit in the Holevo-Frenkel-Weiner communication framework under specific conditions, a result challenging the long-held belief that quantum advantage requires additional resources. The team established this “supremacy of qubit communication” by analyzing a scenario where Alice prepares six states and Bob performs a three-outcome measurement, finding that a cryptographic constraint on preparation uniquely favors quantum communication.

This advantage extends to the generation of certified randomness without any initial seed input for Bob, and this advantage persists even with communication noise. The work introduces a “witness” to identify quantum strategies beyond classical capabilities.

Qubit Supremacy in Holevo-Frenkel-Weiner Framework with Free Shared Randomness

The ability of a qubit to outperform a classical bit in communication relies on a specific setup involving constraints on information preparation and measurement outcomes; researchers demonstrated this advantage exists even when no additional quantum resources are used. This work centers on a scenario where Alice, the sender, prepares six distinct quantum states under cryptographic constraints, while Bob, the receiver, employs a three-outcome measurement to decode the information.