{
  "id": "1009.3307",
  "version": "v1",
  "published": "2010-09-17T01:29:53.000Z",
  "updated": "2010-09-17T01:29:53.000Z",
  "title": "Quantum process tomography with coherent states",
  "authors": [
    "Saleh Rahimi-Keshari",
    "Artur Scherer",
    "Ady Mann",
    "Ali T. Rezakhani",
    "A. I. Lvovsky",
    "Barry C. Sanders"
  ],
  "comment": "18 pages, 2 figures",
  "journal": "New J. Phys. 13, 013006 (2011)",
  "doi": "10.1088/1367-2630/13/1/013006",
  "categories": [
    "quant-ph"
  ],
  "abstract": "We develop an enhanced technique for characterizing quantum optical processes based on probing unknown quantum processes only with coherent states. Our method substantially improves the original proposal [M. Lobino et al., Science 322, 563 (2008)], which uses a filtered Glauber-Sudarshan decomposition to determine the effect of the process on an arbitrary state. We introduce a new relation between the action of a general quantum process on coherent state inputs and its action on an arbitrary quantum state. This relation eliminates the need to invoke the Glauber-Sudarshan representation for states; hence it dramatically simplifies the task of process identification and removes a potential source of error. The new relation also enables straightforward extensions of the method to multi-mode and non-trace-preserving processes. We illustrate our formalism with several examples, in which we derive analytic representations of several fundamental quantum optical processes in the Fock basis. In particular, we introduce photon-number cutoff as a reasonable physical resource limitation and address resource vs accuracy trade-off in practical applications. We show that the accuracy of process estimation scales inversely with the square root of photon-number cutoff.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-09-17T01:29:53.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum process tomography",
      "photon-number cutoff",
      "general quantum process",
      "coherent state inputs",
      "probing unknown quantum processes"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "New Journal of Physics",
      "year": 2011,
      "month": "Jan",
      "volume": 13,
      "number": 1,
      "pages": "013006"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2011NJPh...13a3006R"
    }
  }
}