Quantum phase estimation using squeezed quasi-Bell states

TL;DR

This paper investigates the use of entangled squeezed coherent states for quantum phase estimation, demonstrating potential precision improvements over other continuous-variable states even in the presence of noise and dissipation.

Contribution

It introduces the application of squeezed quasi-Bell states as probe states in quantum phase estimation and analyzes their advantages under ideal and non-ideal conditions.

Findings

Squeezed quasi-Bell states can enhance phase estimation precision.

Entangled squeezed states outperform other continuous-variable states.

Advantages persist despite dissipation and perturbations.

Abstract

In this paper we present a study of the quantum phase estimation problem employing continuous-variable, entangled squeezed coherent (quasi-Bell) states as probe states. We show that their inherent squeezing and entanglement properties might bring advantages, increasing the precision of phase estimation compared to protocols which employ other continuous variable states e.g., two-mode, entangled coherent states or single-mode, squeezed states. We also analyze the phase estimation process considering: i) a linear (unitary) perturbation, and ii) dissipation, and conclude that the use of entangled squeezed coherent states as probe states may still be advantageous even under non-ideal conditions.