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arXiv · 2305.11124

Thermal light in confined dimensions for "laser" cooling with unfiltered sunlight

Amanda Younes·Wesley C. Campbell
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Abstract

Cooling of systems to sub-kelvin temperatures is usually done using either a cold bath of particles or spontaneous photon scattering from a laser field; in either case, cooling is driven by interaction with a well-ordered, cold (i.e. low entropy) system. However, there have recently been several schemes proposed for ``cooling by heating,'' in which raising the temperature of some mode drives the cooling of the desired system faster. We discuss how to cool a trapped ion to its motional ground state using unfiltered sunlight at $5800\,\mathrm{K}$ to drive the cooling. We show how to treat the statistics of thermal light in a single-mode fiber for delivery to the ion, and show experimentally how the black-body spectrum is strongly modified by being embedded in quasi-one-dimension. Quantitative estimates for the achievable cooling rate with our measured fiber-coupled, low-dimensional sunlight show promise for demonstrating this implementation of cooling by heating.

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Amanda Younes, Wesley C. Campbell. 2023-05-18. Thermal light in confined dimensions for "laser" cooling with unfiltered sunlight. https://arxiv.org/abs/2305.11124

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