{
  "id": "1702.08181",
  "version": "v1",
  "published": "2017-02-27T08:26:09.000Z",
  "updated": "2017-02-27T08:26:09.000Z",
  "title": "All-optical, contactless real-space mapping of valley polarization in 2D materials with second harmonic spectroscopy",
  "authors": [
    "F. Hipolito",
    "Vitor M. Pereira"
  ],
  "comment": "7 pages, 5 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "Valley polarization (VP), an induced imbalance in the populations of a multi-valley electronic system, allows emission of second harmonic (SH) light even in centrosymmetric crystals such as graphene. Whereas in systems such as MoS$\\mathrm{_2}$ or BN this adds to their intrinsic quadratic response, SH generation in a multi-valley inversion-symmetric crystal can provide a direct measure of valley polarization. By computing the nonlinear response and characterizing theoretically the respective SH as a function of polarization, temperature, electron density, and degree of VP, we demonstrate the possibility of disentangling and individually quantifying the intrinsic and valley contributions to the SH. A specific experimental setup is proposed to obtain direct quantitative information about the degree of VP and allow its remote mapping. This approach could prove useful for direct, contactless, real-space monitoring of valley injection and other applications of valley transport and valleytronics.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-02-27T08:26:09.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "valley polarization",
      "second harmonic spectroscopy",
      "contactless real-space mapping",
      "2d materials",
      "multi-valley electronic system"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 7,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}