{
  "abstract": "Engineering not only the magnitude but also the dynamics of synaptic weight updates is an important challenge for memristive neuromorphic hardware. Here, we show that Ag modification of TaO$_x$ memristors introduces an electrically selectable degree of freedom in synaptic depression through the interplay between Ag-related and oxygen-vacancy dynamics. Reference devices exhibit conventional bipolar switching, whereas Ag-modified devices display symmetric table-with-legs hysteresis loops, metastable intermediate states, and a strongly non-monotonic dependence of depression dynamics on programming amplitude. By varying only the pulse amplitude, the same device can be driven among three regimes: gradual sigmoidal depression, an abrupt update concentrated within a few pulses, and a broadly distributed evolution extending over more than one hundred pulses. A minimal coupled-state model, in which a vacancy-related switching variable interacts with a slower Ag-related internal degree of freedom, reproduces this gradual--abrupt--gradual crossover using two individually monotonic field-activated processes. The functional impact is assessed in a memristor-based multilayer perceptron. For MNIST, the abrupt, sigmoidal, and slowly evolving responses yield accuracies of approximately 50%, 85%, and 88%, respectively, while the gradual regime reaches approximately 72% for Fashion-MNIST. These results show that coupling Ag-related and oxygen-vacancy dynamics can transform synaptic depression from a fixed device characteristic into an electrically programmable property.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.37204",
  "author_total": 7,
  "authors": [
    {
      "name": "R. Leal Martir"
    },
    {
      "name": "W. Quiñonez"
    },
    {
      "name": "A. J. T. van der Ree"
    },
    {
      "name": "M. H. Aguirre"
    },
    {
      "name": "G. Palasantzas"
    },
    {
      "name": "M. J. Sánchez"
    },
    {
      "name": "D. Rubi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7fj3q6p9eb9py.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.37204",
  "fulltext_url": null,
  "id": "7fj3q6p9eb9py",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.37204",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "openalex",
      "2208|Advanced Memory and Neural Computing"
    ]
  ],
  "openalex": "W7214928807",
  "pdf_url": "https://arxiv.org/pdf/2609.37204",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7fj3q6p9eb9py.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.37204",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.37204"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Engineering Synaptic Dynamics in Ag-Modified TaO$_x$ Memristive Devices",
  "title_text": "Engineering Synaptic Dynamics in Ag-Modified TaO_x Memristive Devices",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/7fj3q6p9eb9py",
  "venue": "arXiv",
  "versions": []
}