Work

Theory of Quantum-Enhanced Interferometry with General Markovian Light Sources

Year: 2026

Type: article

Abstract: Quantum optical systems comprising quantum emitters interacting with engineered optical modes generate non-classical states of light that can be used as resource states for quantum-enhanced interferometry. However, outside of well-controlled systems producing either single-mode states (e.g. Fock states or squeezed states) or highly symmetric multi-mode states (e.g. superradiant states), their potential for quantum advantage remains uncharacterized. In this work, we develop a framework to analyze quantum enhanced interferometry with general Markovian quantum light sources. First, by connecting the quantum Fisher information (QFI) of the photons emitted by a source to the multi-time correlation functions and the source dynamics, we elucidate the link between the level structure and spectrum of the source to a potential quantum advantage in interferometry. Second, we analyze optimal measurement protocols that can be used to achieve this quantum advantage with experimentally available optical elements. In particular, we show that tunable optical elements with Kerr non-linearity can always be harnessed to implement the optimal measurement for any given source. Simultaneously, we also outline general conditions under which linear optics and photodetection is enough to implement the optimal measurement.

Source: PRX Quantum

DOI: 10.1103/dmhd-pyct

Authors: Erfan Abbasgholinejad, Daniel Malz, Ana Asenjo-Garcia, Rahul Trivedi

Institutions: University of Washington, University of Copenhagen, Columbia University, Max Planck Institute of Quantum Optics

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,450