Experimental memory control in continuous variable optical quantum reservoir computing

• DOI: 10.1038/s41566-026-01880-9
• ArXiv number: 2506.07279

Quantum reservoir computing (QRC) offers a promising framework for online quantum-enhanced machine learning tailored to temporal tasks, yet practical implementations with native memory capabilities remain limited. Here, we demonstrate an optical QRC platform based on deterministically generated multimode squeezed states, exploiting both spectral and temporal multiplexing in a fully continuous-variable (CV) setting, and enabling controlled fading memory. Data is encoded via programmable phase shaping of the pump in an optical parametric process and retrieved through mode-selective homodyne detection. Real-time memory is achieved through feedback using electro-optic phase modulation, while long-term dependencies are achieved via spatial multiplexing. This architecture with minimal post-processing performs nonlinear temporal tasks, including parity checking and chaotic signal forecasting, with results corroborated by a high-fidelity Digital Twin. We show that leveraging the entangled multimode structure significantly enhances the expressivity and memory capacity of the quantum reservoir. This work establishes a scalable photonic platform for quantum machine learning, operating in CV encoding and supporting practical quantum-enhanced information processing.

• Full paper

Related research projects

QUANTCOM

Exploring the Intersection of Quantum Phenomena and Next-Generation Computing

P.I.: Gian Luca Giorgi

Emerging properties of driven-dissipative nonlinear quantum oscillators offer a unique advantage in terms of processing capacity, making these systems strong candidates for real-world applications in a variety of quantum technology contexts. They …

QNet

Transport, metastability, and neuromorphic applications in quantum networks

P.I.: Gian Luca Giorgi, Roberta Zambrini

QNet is a European project funded under the call Quantera 2023. The consortium is coordinated by Ticijana Ban from the Institute of Physics, Zagreb, and is also composed of IFISC, Universität des …

CoQuSy-CSIC

Complex Quantum Systems: machine learning, thermodynamics, and emergent phenomena

P.I.: Gonzalo Manzano, Roberta Zambrini

CoQuSy is a coordinated project and joins all the researchers at IFISC (belonging either to CSIC or UIB) working in the common line of complex quantum systems. The coordination is motivated by …

CoQuSy-UIB

Complex Quantum Systems: machine learning, thermodynamics, and emergent phenomena

P.I.: Gian Luca Giorgi

CoQuSy is a coordinated project and joins all the researchers at IFISC (belonging either to CSIC or UIB) working in the common line of complex quantum systems. The coordination is motivated by …

INFOLANET

Information processing with coupled laser networks

P.I.: Apostolos Argyris, Miguel C. Soriano

In the INFOLANET project, we will combine the expertise of the PIs on dynamical systems and machine learning to advance information processing concepts, based on a high-speed photonic implementation. We anticipate that …

Quantum Spain

Quantum Spain

P.I.: Roberta Zambrini

Reserach topic: QUANTUM MACHINE LEARNING Convenio en el BOE: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2023-18333 IFISC participation both as UIB and as CSIC (2 separate budgets)

MdM-IFISC-2

Maria de Maeztu 2023-2026

P.I.: Ernesto Estrada, Ingo Fischer, Emilio Hernández-García, Rosa Lopez, Claudio Mirasso, Jose Javier Ramasco, Raúl Toral, Roberta Zambrini

After 15 years of its existence, IFISC can point to a proven track record of impactful research. The previous 2018-2022 MdM award has significantly enhanced the institute's capabilities, as demonstrated by an …

Related News

Programming light’s memory: A new step in Quantum Computing

March 26, 2026

The study published in Nature Photonics shows, for the first time, how to exploit a quantum system of light equipped with controllable memory, enabling learning and prediction of complex signals.The research is the result of a collaboration between Laboratoire Kastler …

Programar la memòria de la llum: un nou pas cap a la computació quàntica

March 26, 2026

L'estudi, publicat a Nature Photonics, mostra per primera vegada com explotar un sistema quàntic de llum dotat de memòria controlable, la qual cosa permet aprendre i predir senyals complexos.La recerca és fruit d'una col·laboració entre el Laboratoire Kastler Brossel (LKB, …

Programar la memoria de la luz: un nuevo paso hacia la computación cuántica

March 26, 2026

El estudio, publicado en Nature Photonics, muestra por primera vez cómo explotar un sistema cuántico de luz dotado de memoria controlable, lo que permite aprender y predecir señales complejas.La investigación es fruto de una colaboración entre el Laboratoire Kastler Brossel …