Helicity decoupling ultrastrong Rabi splitting from quantum vacuum dressing

Abstract:Polaritons and quantum vacuum dressing are usually regarded as intertwined consequences of ultrastrong light-matter coupling. Here we show that they can be controlled independently through helicity. We consider cyclotron resonance coupled to a chiral cavity supporting a single circular mode. When the helicity of the cavity field matches the cyclotron motion, energy is exchanged resonantly between light and matter, producing a large Rabi splitting and conventional polaritons, while the ground state remains the bare vacuum. Reversing the magnetic field reverses the cyclotron motion without changing the cavity. The same mode then couples through anomalous processes that create and annihilate light and matter excitations in pairs: the conventional polaritonic anticrossing disappears, while the ground state acquires squeezing and virtual excitations. These two regimes show that spectral hybridization and quantum vacuum dressing are distinct manifestations of ultrastrong coupling, and that a large Rabi splitting alone does not imply a dressed quantum vacuum. Helicity therefore provides a route to controlling polariton formation and quantum correlations as distinct resources in cavity quantum materials.

Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)

arXiv:2610.10944 [quant-ph]

(or arXiv:2610.10944v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2610.10944 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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