Theory of coherent interaction-free detection of pulses

Loading...
Thumbnail Image

Access rights

openAccess

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2023-07

Major/Subject

Mcode

Degree programme

Language

en

Pages

16
1-16

Series

PHYSICAL REVIEW RESEARCH, Volume 5, issue 3

Abstract

Quantum physics allows an object to be detected even in the absence of photon absorption, by the use of so-called interaction-free measurements. We provide a formulation of this protocol using a three-level system, where the object to be detected is a pulse coupled resonantly into the second transition. In the original formulation of interaction-free measurements, the absorption is associated with a projection operator onto the third state. We perform an in-depth analytical and numerical analysis of the coherent protocol, where coherent interaction between the object and the detector replaces the projective operators, resulting in higher detection efficiencies. We provide approximate asymptotic analytical results to support this finding. We find that our protocol reaches the Heisenberg limit when evaluating the Fisher information at small strengths of the pulses we aim to detect - in contrast to the projective protocol that can only reach the standard quantum limit. We also demonstrate that the coherent protocol remains remarkably robust under errors such as pulse rotation phases and strengths, the effect of relaxation rates and detunings, as well as different thermalized initial states.

Description

Funding Information: We acknowledge financial support from the Finnish Center of Excellence in Quantum Technology QTF (Projects No. 312296, No. 336810, and No. 352925) of the Academy of Finland and from Business Finland QuTI (Decision No. 41419/31/2020). Publisher Copyright: © 2023 authors. Published by the American Physical Society.

Keywords

Other note

Citation

McCord , J J , Dogra , S & Paraoanu , G S 2023 , ' Theory of coherent interaction-free detection of pulses ' , PHYSICAL REVIEW RESEARCH , vol. 5 , no. 3 , 033012 , pp. 1-16 . https://doi.org/10.1103/PhysRevResearch.5.033012