Signal detection without finite-energy limits to quantum resolution

TL;DR

This paper demonstrates that certain simple quantum signal detection schemes can achieve unlimited resolution regardless of energy constraints, with lower energy sometimes yielding better resolution.

Contribution

It introduces a class of signal detection schemes where resolution is not limited by energy, challenging traditional assumptions about energy constraints in quantum measurement.

Findings

Resolution can be increased with lower energy in these schemes.

The effectiveness depends on the deviation of the probe state from minimum-uncertainty states.

Energy is not a limiting factor for resolution in the proposed schemes.

Abstract

We show that there are extremely simple signal detection schemes where the finiteness of energy resources places no limit to the resolution. On the contrary, larger resolution can be obtained with lower energy. To this end the generator of the signal-dependent transformation encoding the signal information on the probe state must be different from the energy. We show that the larger the deviation of the probe state from being minimum-uncertainty state, the better the resolution.