Probing many-body correlations using quantum-cascade correlation spectroscopy

Year: 2024

Authors: Scarpelli L., Elouard C., Johnsson M., Morassi M., Lemaitre A., Carusotto I., Bloch J., Ravets S., Richard M., Volz T.

Autors Affiliation: Macquarie Univ, Sch Math & Phys Sci, Sydney, NSW, Australia; Macquarie Univ, ARC Ctr Excellence Engn Quantum Syst, Sydney, NSW, Australia; Ctr Lyon, Inria, Villeurbanne, France; ENS Lyon, LIP, Lyon, France; Univ Lorraine, LPCT, CNRS, Vandoeuvre Les Nancy, France; Univ Paris Saclay, Ctr Nanosci & Nanotechnol C2N, CNRS, Palaiseau, France; Univ Trento, Pitaevskii BEC Ctr, CNR INO, Trento, Italy; Univ Trento, Dipartimento Fis, Trento, Italy; CNRS UCA SU NUS NTU Int Joint Res Unit, MajuLab, Singapore, Singapore; Natl Univ Singapore, Ctr Quantum Technol, Singapore, Singapore.

Abstract: In quantum optics, the radiative quantum cascade-the consecutive emission of photons from a ladder of energy levels-is of fundamental importance. Two-photon cascaded emission has been instrumental in pioneering experiments to test Bell inequalities and generate entangled photon pairs. More recently, correlated and entangled photon pairs in the visible and microwave domains have been demonstrated using solid-state systems. These experiments rely on the nonlinear nature of the underlying energy ladder, which enables the direct excitation and probing of specific single-photon transitions. Here we use exciton-polaritons to explore the cascaded emission of photons in the regime where individual transitions of the ladder are not resolved. We excite a polariton quantum cascade by off-resonant laser excitation and probe the emitted luminescence using a combination of spectral filtering and correlation spectroscopy. The measured photon-photon correlations exhibit a strong dependence on the polariton energy and therefore on the underlying polaritonic interaction strength, with clear signatures of many-body Feshbach resonances. Our experiment establishes photon cascade correlation spectroscopy as a highly sensitive tool to study the underlying quantum properties of novel semiconductor materials and many-body quantum phenomena. Quantum-correlated photons typically characterize strongly nonlinear quantum emitters. A two-photon correlation spectroscopy method now provides a powerful probe of weakly nonlinear many-body quantum systems.

Journal/Review: NATURE PHYSICS

Volume: 20 (2)      Pages from: 177  to: 178

More Information: We would like to thank G. M. Matutano and A. Wood for early experimental work, and A. Auffeves for early contributions towards the theoretical modelling. We also thank D. D. Bernardis for discussions. We acknowledge financial support from the Australian Research Council Centre of Excellence for Engineered Quantum Systems EQUS (CE170100009). I.C. acknowledges financial support from the Provincia Autonoma di Trento, from the Q@TN initiative and from PNRR MUR project PE0000023-NQSTI. C2N acknowledges support from the Paris Ile-de-France Region in the framework of DIM SIRTEQ, the French RENATECH network, the H2020-FETFLAG project PhoQus (820392), the QUANTERA project Interpol (ANR-QUAN-0003-05) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project ARQADIA, grant agreement no. 949730). M.R. acknowledges support from the Centre for Quantum Technologies’s Exploratory Initiative program.
KeyWords: Ladders; Laser excitation; Particle beams; Polariton; Quantum entanglement; Quantum optics; Semiconductor materials; Bell´s inequality; Cascade correlation; Correlation spectroscopy; Energy; Entangled photon pairs; Many body; Many-body correlations; Polaritons; Quantum cascades; Two photon; Photons
DOI: 10.1038/s41567-023-02322-x

Citations: 3
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here