The Magic Scroll: Leveraging biased noise to improve magic state cultivation in register-based architectures

• URL: http://arxiv.org/abs/2608.09018v1
• Date: Mon, 10 Aug 2026 02:19:01 GMT
• Title: The Magic Scroll: Leveraging biased noise to improve magic state cultivation in register-based architectures
• Abstract summary: We present efficient methods for implementing 6.6.6 and 4.8.8 colour codes, as well as bilayer and folded surface codes, using two-qubit registers.<n>We show how register-based architectures can improve error rates and reduce quantum volumes in fault-tolerant quantum computing.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Multiple quantum computing platforms across neutral atoms [1], nitrogen vacancy centres [2, 3], gate-defined dots [4-6] and 14|15 phosphorus atom qubits [7, 8] in silicon are experimentally exploring the use of high connectivity qubits, beyond that of nearest-neighbour planar lattices. Theoretical works consider modifications to fault-tolerant codes to leverage this higher qubit connectivity, such as non-local LDPC codes [9], inspiring superconducting [10] and photonic [11] platforms to also seek non-planar connectivity. In addition, separate theoretical works consider biased noise, where bit- and phase-flip errors are not equally likely. In this work, we present efficient methods for implementing 6.6.6 and 4.8.8 colour codes, as well as bilayer and folded surface codes, using two-qubit registers. We also leverage noise bias to avoid hook errors, demonstrating comparable performance to the surface code. By combining colour and bilayer codes, we show how magic state cultivation procedures [12-14] can be improved, in a procedure we refer to as the Magic Scroll. Not only does the Magic Scroll escape to a standard surface code, it also improves cultivation volumes by 3x and supports magic $|T\rangle$ state fidelities as low as $10^{-9}$. We show that this technique can be further leveraged to improve distillation performance, showing a 3x improvement to distillation volumes for error rates of $\sim 10^{-15}$. Through these constructions, we demonstrate techniques to leverage noise bias and high qubit connectivity, showing how register-based architectures can improve error rates and reduce quantum volumes in fault-tolerant quantum computing.

Related papers

• On the Design of Qwen3.8-Next Architecture: Evaluation, Efficiency, and Training Stability [57.03393882933515]
  We describe the architecture and ablations of Qwen3.8-Flash-Next, a sparse mixture-of-experts model with 125B parameters, 6B activated per token, and 51B parameters of n-gram embedding tables held off the accelerator.<n>On fourteen pre-training benchmarks the model leads the 397B-A17B predecessor on eight and trails it on the rest by at most 2.6 points, at 1/3 the activated parameters, 1/3 the training tokens, and roughly 1/9 the training FLOPs.
  arXiv  Detail & Related papers  (2026-08-31T06:35:07Z)
• Towards Ultra-High-Rate Quantum Error Correction with Reconfigurable Atom Arrays [8.259838694706275]
  New structural conditions on the underlying affine permutation matrices make encoding rates exceeding $1/2$ compatible with efficient implementation on neutral atom arrays.<n>Co-designed family of ultra-high-rate quantum codes that supports efficient syndrome extraction and atom rearrangement.
  arXiv  Detail & Related papers  (2026-04-17T16:19:55Z)
• Enhancing Kerr-Cat Qubit Coherence with Controlled Dissipation [64.05054054401175]
  Kerr-cat qubit (KCQ) is a bosonic quantum processor.<n>KCQs are experimentally compatible with on-chip architectures and high-fidelity operations.<n>We present direct evidence that the bit-flip time in a KCQ is limited by leakage out of the qubit manifold.
  arXiv  Detail & Related papers  (2025-11-02T17:58:36Z)
• Unfolded distillation: very low-cost magic state preparation for biased-noise qubits [1.8749305679160366]
  We propose a low-cost magic state distillation scheme for biased-noise qubits.<n>The logical fidelity remains nearly identical even at a more modest noise bias of $eta gtrsim 80$.<n>Our construction is based on unfolding the $X$ stabilizer group of the Hadamard 3D quantum Reed-Muller code in 2D.
  arXiv  Detail & Related papers  (2025-07-16T18:00:00Z)
• Breaking even with magic: demonstration of a high-fidelity logical non-Clifford gate [1.6986469299341722]
  We propose a magic-state preparation protocol to fault-tolerantly prepare a pair of logical magic states in a quantum error-detecting code using only eight physical qubits.<n>We show that this protocol can be self-concatenated to produce extremely high-fidelity magic states with low space-time overhead.
  arXiv  Detail & Related papers  (2025-06-17T16:23:47Z)
• Demonstrating dynamic surface codes [118.67046728951689]
  We experimentally demonstrate three time-dynamic implementations of the surface code.<n>First, we embed the surface code on a hexagonal lattice, reducing the necessary couplings per qubit from four to three.<n>Second, we walk a surface code, swapping the role of data and measure qubits each round, achieving error correction with built-in removal of accumulated non-computational errors.<n>Third, we realize the surface code using iSWAP gates instead of the traditional CNOT, extending the set of viable gates for error correction without additional overhead.
  arXiv  Detail & Related papers  (2024-12-18T21:56:50Z)
• Scaling and logic in the color code on a superconducting quantum processor [109.61104855764401]
  We present a demonstration of the color code on a superconducting processor, achieving logical error suppression and performing logical operations.<n>We inject magic states, a key resource for universal computation, achieving fidelities exceeding 99% with post-selection.<n>This work establishes the color code as a compelling research direction to realize fault-tolerant quantum computation on superconducting processors.
  arXiv  Detail & Related papers  (2024-12-18T19:00:05Z)
• Low-overhead magic state distillation with color codes [1.3980986259786223]
  Fault-tolerant implementation of non-Clifford gates is a major challenge for achieving universal fault-tolerant quantum computing.<n>We propose two distillation schemes based on the 15-to-1 distillation circuit and lattice surgery, differing in their methods for handling faulty rotations.<n>To reach a given target infidelity, our schemes require approximately two orders of magnitude fewer resources than the previous best magic state distillation schemes for color codes.
  arXiv  Detail & Related papers  (2024-09-12T02:20:17Z)
• Quantum computation on a 19-qubit wide 2d nearest neighbour qubit array [59.24209911146749]
  This paper explores the relationship between the width of a qubit lattice constrained in one dimension and physical thresholds. We engineer an error bias at the lowest level of encoding using the surface code. We then address this bias at a higher level of encoding using a lattice-surgery surface code bus.
  arXiv  Detail & Related papers  (2022-12-03T06:16:07Z)
• The cost of universality: A comparative study of the overhead of state distillation and code switching with color codes [63.62764375279861]
  We compare two leading FT implementations of the T gate in 2D color codes under circuit noise. We find a circuit noise threshold of 0.07(1)% for the T gate via code switching, almost an order of magnitude below that achievable by state distillation in the same setting.
  arXiv  Detail & Related papers  (2021-01-06T19:00:01Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.