Quantum state engineering of levitated systems for sensing and information processing

Abstract:

Levitated quantum systems, ranging from trapped atoms and ions to mesoscopic particles, provide exceptional isolation from the environment and access to controllable motional degrees of freedom. Their full potential emerges from the interplay between motional, internal, and photonic degrees of freedom. Such hybrid architectures combine the high information capacity of continuous variables with the addressability and readout capabilities of discrete degrees of freedom, opening new possibilities for quantum sensing, information processing, and tests of fundamental physics. Recent advances in coherent control of motional quantum systems raise the question of how far these resources can be pushed beyond the Gaussian regime and utilized under realistic experimental conditions.

In the talk, I will present the following approaches to quantum state engineering and sensing with levitated systems.

(i) Universal control of motion via nonharmonic potentials: Optimal modulation of weakly nonharmonic trapping potentials enables deterministic preparation of quantum non-Gaussian states, including Fock, Schrödinger-cat, and Gottesman–Kitaev–Preskill states, as well as implementation of arbitrary unitaries within selected subspaces [1,3].

(ii) Large-scale motional quantum resources: Dynamical evolution in engineered nonlinear potentials enables rapid generation of large-scale non-Gaussian states and entangled motional resources, including macroscopic superpositions and mechanical Bell states [2,3].

(iii) Quantum-enhanced sensing with motional states: Quantum optimal control identifies families of non-Gaussian states that maximize sensitivity to weak forces under realistic decoherence. I will discuss phase-insensitive displacement sensing, distributed sensing protocols, and recent results demonstrating that quantum advantage can persist even without complete ground-state cooling [4–6].

These approaches provide a unified framework for engineering and exploiting nonclassical motional states across a wide range of platforms. Finally, I will outline ongoing directions involving neutral atoms, spin–photon–phonon quantum nodes, superradiance-enhanced tabletop sensing, cavity-QED-enhanced gravitational interferometry, and quantum sensing with atoms in optical tweezers.

[1] PTG, H. Pichler, C. A. Regal, O. Romero-Isart, Quantum control of continuous systems via nonharmonic potential modulation, Quantum 9, 1824 (2025)
[2] M. Roda-Llordes, A. Riera-Campeny, D. Candoli, PTG, O. Romero-Isart, Macroscopic quantum superpositions via dynamics in a wide double-well potential, Phys. Rev. Lett. 132, 023601 (2024)
[3] PTG, O. Romero-Isart, Quantum Non-Gaussian State Preparation of Levitated Particles via Time-Dependent Control of Weakly Nonharmonic Hybrid Potentials, arXiv:2606.10042 (2026)
[4] PTG, R. Filip, Optimal Phase-Insensitive Force Sensing with Non-Gaussian States, Phys. Rev. Lett. 135, 230802 (2025)
[5] PTG, M. Fadel, R. Filip, Distributed Phase-Insensitive Displacement Sensing, arXiv:2602.03727 (2026)
[6] PTG, To Cool, or Not to Cool? Displacement Sensing with Hot Quantum States, arXiv:2606.13650 (2026)