dorsal/arxiv
View SchemaBreakdown of the few-level approximation in collective systems
| Authors | M. Kiffner, J. Evers, C. H. Keitel |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0611071 |
| URL | https://arxiv.org/abs/quant-ph/0611071 |
| DOI | 10.1103/PhysRevA.76.013807 |
| Journal | Phys. Rev. A 76, 013807 (2007) |
Abstract
The validity of the few-level approximation in dipole-dipole interacting collective systems is discussed. As example system, we study the archetype case of two dipole-dipole interacting atoms, each modelled by two complete sets of angular momentum multiplets. We establish the breakdown of the few-level approximation by first proving the intuitive result that the dipole-dipole induced energy shifts between collective two-atom states depend on the length of the vector connecting the atoms, but not on its orientation, if complete and degenerate multiplets are considered. A careful analysis of our findings reveals that the simplification of the atomic level scheme by artificially omitting Zeeman sublevels in a few-level approximation generally leads to incorrect predictions. We find that this breakdown can be traced back to the dipole-dipole coupling of transitions with orthogonal dipole moments. Our interpretation enables us to identify special geometries in which partial few-level approximations to two- or three-level systems are valid.
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"abstract": "The validity of the few-level approximation in dipole-dipole interacting\ncollective systems is discussed. As example system, we study the archetype case\nof two dipole-dipole interacting atoms, each modelled by two complete sets of\nangular momentum multiplets. We establish the breakdown of the few-level\napproximation by first proving the intuitive result that the dipole-dipole\ninduced energy shifts between collective two-atom states depend on the length\nof the vector connecting the atoms, but not on its orientation, if complete and\ndegenerate multiplets are considered. A careful analysis of our findings\nreveals that the simplification of the atomic level scheme by artificially\nomitting Zeeman sublevels in a few-level approximation generally leads to\nincorrect predictions. We find that this breakdown can be traced back to the\ndipole-dipole coupling of transitions with orthogonal dipole moments. Our\ninterpretation enables us to identify special geometries in which partial\nfew-level approximations to two- or three-level systems are valid.",
"arxiv_id": "quant-ph/0611071",
"authors": [
"M. Kiffner",
"J. Evers",
"C. H. Keitel"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.76.013807",
"journal_ref": "Phys. Rev. A 76, 013807 (2007)",
"title": "Breakdown of the few-level approximation in collective systems",
"url": "https://arxiv.org/abs/quant-ph/0611071"
},
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