- Accepted Paper
Identical-particle symmetry-enabled complete coherent control of ultracold atomic and molecular collisions
Phys. Rev. A - Accepted 15 September, 2026
DOI: https://doi.org/10.1103/1mcm-jmnx
Phys. Rev. A - Accepted 15 September, 2026
DOI: https://doi.org/10.1103/1mcm-jmnx
We show that exchange symmetry in collisions of identical particles enables symmetry-protected coherent control of the total scattering cross section. For identical fermions, antisymmetrization enforces a common control phase among contributing channels within a given parity sector, yielding maximal control visibility. For identical bosons, phase-locking persists but with reduced visibility due to additional exchange (satellite) contributions. Collisions of distinguishable particles lack this symmetry-imposed phase-locking, leading to lower controllability and visibility. We elucidate these principles through coupled-channel quantum-scattering calculations for lithium–lithium collisions, comparing the (identical fermions), (identical bosons), and (distinguishable) systems. Furthermore, in the identical-particle cases, symmetry-enforced phase-locking enables full control over the parity of the final state even beyond the ultracold regime. This mechanism is broadly applicable to identical-particle collisions, including homonuclear molecules for which established approaches—DC electric fields or microwave shielding—are ineffective or unavailable.
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