{
  "abstract": "Fault-Tolerant Quantum Computers (FTQCs) commonly use the surface code to encode program qubits as error-corrected logical qubits. Unfortunately, the surface code has a poor encoding rate, so recent work has proposed Yoked Surface Codes (YSCs), which concatenate the surface code with a high-rate quantum code. The surface code qubits in YSCs are protected by the checks, or yokes, of the high-rate code. YSCs have 1D and 2D variants, which are $1.8\\times$ and $4.5\\times$ more efficient than the surface code, respectively. Modern FTQC architectures use a two-level hierarchy: surface codes perform logical operations (compute) while 2D YSCs store idle program qubits (memory). To load a qubit from memory, the FTQC first performs retrieval, which logically moves a program qubit from a 2D YSC into a surface code (8 cycles). However, retrieval is not fault-tolerant, so the FTQC must verify the load by measuring all the yokes of the 2D YSC (178 cycles). As verification dominates memory access latency, eliminating it can provide a speedup of $5.7\\times$. Our goal is to reduce the verification overhead of 2D YSCs while retaining their storage efficiency. We exploit the fact that 1D YSCs, though less storage-efficient, incur negligible verification latency. We propose Trident, which expands the two-level hierarchy into a three-level hierarchy by adding a small intermediate level containing a 1D YSC (L1). If most loads hit L1 rather than L2 (2D YSC tier), it can significantly reduce verification overhead. We present two variants: Trident-D (demand-driven) and Trident-P (prefetch-driven), which achieve speedups of $2.8\\times$ and $4.2\\times$, respectively, while increasing the physical qubit cost of memory by only 4.9%.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.32152",
  "author_total": 5,
  "authors": [
    {
      "name": "Gunagya Singh Mamak"
    },
    {
      "name": "Suhas Vittal"
    },
    {
      "name": "Kabir Dubey"
    },
    {
      "name": "Kaitlin N. Smith"
    },
    {
      "name": "Moinuddin K. Qureshi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bb42t4wd615mx.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.32152",
  "fulltext_url": null,
  "id": "bb42t4wd615mx",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.32152",
  "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",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Computing Algorithms and Architecture"
    ]
  ],
  "openalex": "W7223659196",
  "pdf_url": "https://arxiv.org/pdf/2610.32152",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bb42t4wd615mx.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:15Z",
      "native_id": "2610.32152",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.32152"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Trident: Efficient Load Verification for Yoked Surface Codes using a Three-Level Memory Hierarchy",
  "title_text": "Trident: Efficient Load Verification for Yoked Surface Codes using a Three-Level Memory Hierarchy",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:15Z",
  "url": "https://research.draconitic.com/paper/bb42t4wd615mx",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1145/3845814.3850031",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}