{
  "id": "1609.02474",
  "version": "v1",
  "published": "2016-09-08T15:51:17.000Z",
  "updated": "2016-09-08T15:51:17.000Z",
  "title": "Thermopower of molecular junctions: Tunneling to hopping crossover in DNA",
  "authors": [
    "Roman Korol",
    "Michael Kilgour",
    "Dvira Segal"
  ],
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We study the electrical conductance $G$ and the thermopower $S$ of single-molecule junctions, and reveal signatures of different transport mechanisms: off-resonant tunneling, on-resonant coherent (ballistic) motion, and multi-step hopping. These mechanisms are identified by studying the behavior of $G$ and $S$ while varying molecular length and temperature. Based on a simple one-dimensional model for molecular junctions, we derive approximate expressions for the thermopower in these different regimes. Analytical results are compared to numerical simulations, performed using a variant of B\\\"uttiker's probe technique, the so-called voltage-temperature probe, which allows us to phenomenologically introduce environmentally-induced elastic and inelastic electron scattering effects, while applying both voltage and temperature biases across the junction. We further simulate the thermopower of GC-rich DNA molecules with mediating A:T blocks, and manifest the tunneling-to-hopping crossover in both the electrical conductance and the thermopower, in accord with measurements by Y. Li et al., Nature Comm. 7, 11294 (2016).",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-09-08T15:51:17.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "molecular junctions",
      "thermopower",
      "hopping crossover",
      "electrical conductance",
      "gc-rich dna molecules"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}