{
  "annotation_id": "4b37720f-7952-419a-8535-db436b90f2bd",
  "date_created": "2026-03-02T18:01:35.595000Z",
  "date_modified": "2026-03-02T18:01:35.595000Z",
  "file_hash": "e22207e9ab39d87bc50bd955d69a4f9e3b745397b8f2136f11529ac7a492520b",
  "private": false,
  "record": {
    "abstract": "Neutral fermions of spin $\\frac 12$ with magnetic moment can interact with\nelectromagnetic fields through nonminimal coupling. The Dirac--Pauli equation\nfor such a fermion coupled to a spherically symmetric or central electric field\ncan be reduced to two simultaneous ordinary differential equations by\nseparation of variables in spherical coordinates. For a wide variety of central\nelectric fields, bound-state solutions of critical energy values can be found\nanalytically. The degeneracy of these energy levels turns out to be numerably\ninfinite. This reveals the possibility of condensing infinitely many fermions\ninto a single energy level. For radially constant and radially linear electric\nfields, the system of ordinary differential equations can be completely solved,\nand all bound-state solutions are obtained in closed forms. The radially\nconstant field supports scattering solutions as well. For radially linear\nfields, more energy levels (in addition to the critical one) are infinitely\ndegenerate. The simultaneous presence of central magnetic and electric fields\nis discussed.",
    "arxiv_id": "quant-ph/0001031",
    "authors": [
      "Qiong-gui Lin"
    ],
    "categories": [
      "quant-ph",
      "hep-th"
    ],
    "doi": "10.1103/PhysRevA.61.022101",
    "journal_ref": "Phys.Rev. A61 (2000) 022101",
    "title": "Bound states of neutral particles in external electric fields",
    "url": "https://arxiv.org/abs/quant-ph/0001031"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "b2119597-aa17-444c-90e6-a7a6004aeb27",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}