Choice of measurement as signal

TL;DR

This paper demonstrates that in quantum mechanics, non-selective measurements on entangled particles can enable communication by encoding signals in the measurement basis, unlike classical systems.

Contribution

It introduces a protocol where non-selective measurements on entangled states facilitate communication through basis choice, highlighting a quantum advantage.

Findings

Non-selective measurements can transmit information in quantum systems.

Measurement basis choice encodes the communication signal.

Protocol works in Hilbert spaces of odd prime dimension.

Abstract

In classical mechanics, performing a measurement without reading the measurement outcome is equivalent to not exploiting the measurement at all. A non-selective measurement in the classical realm carries no information. Here we show that the situation is remarkably different when quantum mechanical systems are concerned. A non-selective measurement on one part of a maximally entangled pair can allow communication between two parties. In the proposed protocol, the signal is encoded in the choice of the measurement basis of one of the communicating parties, while the outcomes of the measurement are irrelevant for the communication and therefore may be discarded. Different choices for the (non-selective) measurement basis correspond to different signals. The scheme is studied in a Hilbert space of odd prime dimension