Sub-shot-noise-limited phase estimation via SU(1,1) interferometer with thermal states

TL;DR

This paper theoretically demonstrates that an SU(1,1) interferometer using thermal and squeezed vacuum states with parity detection can surpass the shot-noise limit and approach the Heisenberg limit in phase sensitivity.

Contribution

It introduces a novel analysis of phase sensitivity in SU(1,1) interferometers with thermal states, showing potential for enhanced quantum metrology.

Findings

Phase sensitivity beats the shot-noise limit.

Approaches the Heisenberg limit with more input photons.

Thermal states can be effectively used in quantum interferometry.

Abstract

We theoretically study the phase sensitivity of an SU(1,1) interferometer with a thermal state and squeezed vacuum state as inputs and parity detection as measurement. We find that phase sensitivity can beat the shot-noise limit and approaches the Heisenberg limit with increasing input photon number.