Coherent-state phase concentration by quantum probabilistic amplification

TL;DR

This paper introduces a probabilistic amplification method for coherent states that uses thermal noise addition and photon subtraction to enhance weak states and reduce phase uncertainty, outperforming deterministic amplifiers.

Contribution

The paper presents a new architecture for probabilistic coherent-state amplification using thermal noise and photon subtraction, offering improved phase concentration over deterministic methods.

Findings

Significant reduction in phase uncertainty of weak coherent states.

Effective amplification achieved through thermal noise addition and photon subtraction.

Method is feasible with realistic photon-number resolving detectors.

Abstract

We propose novel coherent-state phase concentration by probabilistic measurement-induced ampli- fication. The amplification scheme uses novel architecture, thermal noise addition (instead of single photon addition) followed by feasible multiple photon subtraction using realistic photon-number resolving detector. It allows to substantially amplify weak coherent states and simultaneously reduce their phase uncertainty, contrary to the deterministic amplifier.