Tailoring optical Schr\"odinger cat states via orientation-dependent high-harmonic generation in $\rm{H}_2^+$

Ziyang Gan; Ahai Chen; Yuhai Jiang

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arXiv · 2607.21248

Tailoring optical Schr\"odinger cat states via orientation-dependent high-harmonic generation in $\rm{H}_2^+$

Ziyang Gan·Ahai Chen·Yuhai Jiang

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Abstract

We theoretically demonstrate that the molecular orientation angle $\theta$ provides a structurally intrinsic, continuously tunable control parameter for engineering optical Schr\"{o}dinger cat states via high-harmonic generation (HHG) in H$_2^+$. Coupling time-dependent Schr\"{o}dinger equation simulations to the fully quantized HHG framework, we evaluate the Wigner functions of the post-selected harmonic-mode states under two complementary conditioning strategies. Conditioning on resonance-enhanced low-order harmonics exploits the complementary dipole selection rules of the $1\sigma_g\to1\sigma_u$ and $1\sigma_g\to1\pi_u$ transitions, driving a kitten-cat crossover whose direction is opposite in the two channels as $\theta$ is varied. Conditioning on plateau harmonics instead exploits two-center destructive interference, producing a reentrant cat$\to$kitten$\to$cat transition controlled by the order-dependent interference angle $\theta^*(q)$. In both cases the crossover is decoupled from the laser intensity, focal geometry, and molecular density, offering a degree of control with no counterpart in atomic targets.

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Ziyang Gan, Ahai Chen, Yuhai Jiang. 2026-07-23. Tailoring optical Schr\"odinger cat states via orientation-dependent high-harmonic generation in $\rm{H}_2^+$. https://arxiv.org/abs/2607.21248

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