Work

Identical-particle symmetry-enabled complete coherent control of ultracold atomic and molecular collisions

Year: 2026

Type: article

Abstract: 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 $^{6}\mathrm{Li}{-}^{6}\mathrm{Li}$ (identical fermions), $^{7}\mathrm{Li}{-}^{7}\mathrm{Li}$ (identical bosons), and $^{6}\mathrm{Li}{-}^{7}\mathrm{Li}$ (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.

Source: Physical Review A

DOI: 10.1103/1mcm-jmnx

Authors: Jing-Chen Zhang, Adrien Devolder, Timur V. Tscherbul, Paul Brumer, Yu Liu

Institutions: National Institute of Standards and Technology, University of Maryland, College Park, University of Toronto, University of Nevada, Reno

Language: English

Topic: Cold Atom Physics and Bose-Einstein Condensates

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: U.S. Air Force, Air Force Office of Scientific Research

Awards: G1523888516, G4554544164, G7090116110