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arXiv · 2604.18295

Quantum theory for phonon lasing and non-classical state generation in mixed-species and single trapped ions

David Baur·Tanja Behrle·Ivan Rojkov·Jan Jeske·Susanne Yelin·Jonathan Home·Florentin Reiter
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Abstract

In this article we present a comprehensive theoretical investigation of phonon lasing with mixed-species trapped ions, as demonstrated in [T. Behrle, Phys. Rev. Lett. 131 (2023)], employing both a semi-classical mean-field description and a full quantum theory. We derive an analytic expression for the second-order coherence function, confirming the experimental observation of the system's lasing behaviour above threshold. Building on the successful implementation of the two-ion lasing scheme, we propose a novel approach for achieving phonon lasing with a single trapped ion, offering significant experimental advantages and making the implementation of multiple phonon lasers within a single setup feasible. Furthermore, we explore lasing in a squeezed basis and in different regimes of the Lamb-Dicke approximation, highlighting the potential to produce non-classical states with promising applications in precision sensing. Our analysis of a sensing protocol based on squeezed states, using experimentally feasible parameters, shows a sensitivity enhancement of up to two orders of magnitude.

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David Baur, Tanja Behrle, Ivan Rojkov, Jan Jeske, Susanne Yelin, Jonathan Home, Florentin Reiter. 2026-04-20. Quantum theory for phonon lasing and non-classical state generation in mixed-species and single trapped ions. https://arxiv.org/abs/2604.18295

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