Heisenberg-limited interferometry with pair coherent states and parity measurements

TL;DR

This paper explores advanced quantum interferometry techniques using pair coherent states and parity measurements, demonstrating super-sensitivity and super-resolution capabilities that surpass classical limits.

Contribution

It introduces the use of pair coherent states for Heisenberg-limited interferometry with super-resolution, addressing experimental challenges of twin-Fock state production.

Findings

Two-mode squeezed vacuum states achieve Heisenberg-limited sensitivity but not super-resolution.

Pair coherent states enable both super-sensitivity and super-resolution.

Parity measurements are effective in enhancing interferometric performance.

Abstract

After reviewing parity measurement based interferometry with twin-Fock states, which allows for super-sensitivity (Heisenberg-limited) and super-resolution, we consider interferometry with two different superpositions of twin-Fock states, namely two-mode squeezed vacuum states and pair coherent states. This study is motivated by the experimental challenge of producing twin-Fock states on opposite sides of a beam splitter. We find that input two-mode squeezed states, while allowing for Heisenberg-limited sensitivity, do not yield super-resolutions, whereas we that find both are possible with input pair coherent states.