{
  "id": "quant-ph/0011111",
  "version": "v1",
  "published": "2000-11-28T15:27:15.000Z",
  "updated": "2000-11-28T15:27:15.000Z",
  "title": "Local filtering operations on two qubits",
  "authors": [
    "Frank Verstraete",
    "Jeroen Dehaene",
    "Bart De Moor"
  ],
  "comment": "4 pages",
  "journal": "Physical Review A (\\bf 64), 010101(R) (2001).",
  "doi": "10.1103/PhysRevA.64.010101",
  "categories": [
    "quant-ph"
  ],
  "abstract": "We consider one single copy of a mixed state of two qubits and investigate how its entanglement changes under local quantum operations and classical communications (LQCC) of the type $\\rho'\\sim (A\\otimes B)\\rho(A\\otimes B)^{\\dagger}$. We consider a real matrix parameterization of the set of density matrices and show that these LQCC operations correspond to left and right multiplication by a Lorentz matrix, followed by normalization. A constructive way of bringing this matrix into a normal form is derived. This allows us to calculate explicitly the optimal local filterin operations for concentrating entanglement. Furthermore we give a complete characterization of the mixed states that can be purified arbitrary close to a Bell state. Finally we obtain a new way of calculating the entanglement of formation.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2000-11-28T15:27:15.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "local filtering operations",
      "optimal local filterin operations",
      "lqcc operations correspond",
      "mixed state",
      "entanglement"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Phys. Rev. A"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}