{
  "annotation_id": "a6486470-9cb7-4b1a-806b-e29bb1b542d8",
  "date_created": "2026-03-02T18:02:44.539000Z",
  "date_modified": "2026-03-02T18:02:44.539000Z",
  "file_hash": "b66917eabcf5297b9af6524adf9877e69a33f03b2c0ee4c59f926e1f903b558b",
  "private": false,
  "record": {
    "abstract": "The Klein paradox is reassessed by considering the properties of a finite\nsquare well or barrier in the Dirac equation. It is shown that spontaneous\npositron emission occurs for a well if the potential is strong enough. The\nvacuum charge and lifetime of the well are estimated. If the well is wide\nenough, a seemingly constant current is emitted. These phenomena are transient\nwhereas the tunnelling first calculated by Klein is time-independent. Klein\ntunnelling is a property of relativistic wave equations, not necessarily\nconnected to particle emission. The Coulomb potential is investigated in this\ncontext: it is shown that a heavy nucleus of sufficiently large $Z$ will bind\npositrons. Correspondingly, it is expected that as $Z$ increases the Coulomb\nbarrier will become increasingly transparent to positrons. This is an example\nof Klein tunnelling.",
    "arxiv_id": "quant-ph/9806052",
    "authors": [
      "A Calogeracos",
      "N Dombey"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1142/S0217751X99000312",
    "journal_ref": "Int.J.Mod.Phys. A14 (1999) 631-644",
    "title": "Klein Tunnelling and the Klein Paradox",
    "url": "https://arxiv.org/abs/quant-ph/9806052"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "98c6e16c-b7f8-49fc-aa0a-441724ac2ba8",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}