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Observation of bound state self-interaction in a nano-eV atom collider
Published
Author(s)
R Thomas, M. Chilcott, A. Deb, Eite Tiesinga, N. Kjaergaard
Abstract
Quantum mechanical scattering resonances for colliding particles occur when a continuum scattering state couples to a discrete bound state between them. The coupling also causes the bound state to interact with itself via the continuum and leads to a shift in the bound state energy, but, lacking knowledge of the bare bound state energy, measuring this self-energy via the resonance position has remained elusive. Here, we report on the direct observation of self-interaction by using a nano- eV atom collider to track the position of a magnetically-tunable Feshbach resonance through a parameter space spanned by energy and magnetic field. Our system of potassium and rubidium atoms displays a strongly non-monotonic res- onance trajectory with an exceptionally large self-interaction energy arising from an interplay between the Feshbach bound state and a different, virtual bound state at a fixed energy below threshold.
Thomas, R.
, Chilcott, M.
, Deb, A.
, Tiesinga, E.
and Kjaergaard, N.
(2018),
Observation of bound state self-interaction in a nano-eV atom collider, Nature Communications, [online], https://doi.org/10.1038/s41467-018-07375-8, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=925544
(Accessed October 9, 2025)