{
  "id": "2203.07394",
  "version": "v1",
  "published": "2022-03-14T18:00:06.000Z",
  "updated": "2022-03-14T18:00:06.000Z",
  "title": "Tunneling Spectroscopy of Two-Dimensional Materials Based on Via Contacts",
  "authors": [
    "Qingrui Cao",
    "Evan J. Telford",
    "Avishai Benyamini",
    "Ian Kennedy",
    "Amirali Zangiabadi",
    "Kenji Watanabe",
    "Takashi Taniguchi",
    "Cory R. Dean",
    "Benjamin M. Hunt"
  ],
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.supr-con"
  ],
  "abstract": "We introduce a novel planar tunneling architecture for van der Waals heterostructures based on via contacts, namely metallic contacts embedded into through-holes in hexagonal boron nitride (hBN). We use the via-based tunneling method to study the single-particle density of states of two different two-dimensional (2D) materials, superconducting NbSe$_2$ and monolayer graphene in zero magnetic field as well as in the quantum Hall regime. In NbSe$_2$ devices, we characterize the barrier strength and interface disorder, within the Blonder-Tinkham-Klapwijk model, for tunnel barrier thicknesses of 0, 1 and 2 layers of hBN and study the area dependence of the tunneling contacts down to $30^2$ nm$^2$, demonstrating that the effect of interface disorder can be suppressed in the small-area limit. Additionally, we demonstrate that for 0 layers of hBN, we cross over from diffusive to point contacts in the small-area limit. In graphene, we show that reducing the tunneling area can suppress the effects of phonon-assisted tunneling and defects in the hBN barriers. These via-based tunneling devices overcome limitations of other planar tunneling designs and can be used to produce high-quality, ultra-clean tunneling structures from a variety of 2D materials.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-03-14T18:00:06.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "two-dimensional materials",
      "tunneling spectroscopy",
      "small-area limit",
      "interface disorder",
      "van der waals heterostructures"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}