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arXiv · 2610.06209

Cooling and delocalizing thermal oscillators in hollow-core fibers using optical fringes

Soumya Chakraborty·Pardeep Kumar·Gordon K. L. Wong·Claudiu Genes·Nicolas Y. Joly
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Abstract

Trapped particles in hollow-core fibers enable long-range sensing, though advanced control of their in-fiber motion, such as multimodal cooling and squeezing, remains challenging. Here, we present optical interference-based techniques for controlling a fringe-trapped silica nanoparticle inside a fiber. After feedback-cooling its axial and radial motion, we induce axial delocalization (position anti-squeezing) via two approaches. First, non-adiabatic fringe suppression expands position variance by 11.83 ($\pm$0.7) dB to that of the initial cold-state while retaining Gaussian statistics. Second, multi-pass particle positioning at dark fringes increases delocalization to 13.23 ($\pm$0.5) dB relative to the cold-state's variance via inverted potentials, in agreement with stochastic theory. Stronger delocalization produces non-Gaussian states. Our results demonstrate fringe-trapped particles in hollow-core fibers as a versatile platform for long-range sensing and macroscopic quantum physics.

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Soumya Chakraborty, Pardeep Kumar, Gordon K. L. Wong, Claudiu Genes, Nicolas Y. Joly. 2026-10-05. Cooling and delocalizing thermal oscillators in hollow-core fibers using optical fringes. https://arxiv.org/abs/2610.06209

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