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Steady-state entanglement of interacting masses in free space through optimal feedback control

Klemens Winkler1,*, Anton V. Zasedatelev1,2,†, Benjamin A. Stickler3, Uroš Delić1, Andreas Deutschmann-Olek4, and Markus Aspelmeyer1,5,‡

  • 1Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
  • 2Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, FI-00076 Aalto, Finland
  • 3Institute for Complex Quantum Systems, Ulm University, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
  • 4Automation and Control Institute, TU Wien, A-1040 Vienna, Austria
  • 5Institute for Quantum Optics and Quantum Information (IQOQI) Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, A-1090 Vienna, Austria

  • *Contact author: klemens.winkler@univie.ac.at
  • †Contact author: anton.zasedatelev@aalto.fi
  • ‡Contact author: markus.aspelmeyer@univie.ac.at
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Phys. Rev. Research 7, 043298 – Published 16 December, 2025

DOI: https://doi.org/10.1103/hxc8-fxcb

Abstract

We develop a feedback strategy based on optimal quantum feedback control for Gaussian systems to maximize the likelihood of steady-state entanglement detection between two directly interacting masses. We employ linear quadratic Gaussian control to engineer the phase-space dynamics of the two masses and propose Einstein-Podolsky-Rosen-type variance minimization constraints for the feedback to facilitate unconditional entanglement generation. This scheme allows for stationary entanglement in parameter regimes where strategies based on total energy minimization (cooling) would fail.

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Information

Phys. Rev. Research 7, 043298– Published 16 December, 2025
  • Received 5 September 2024
  • Accepted 2 January 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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