Fault-tolerant distributed quantum computing with a single nucleus per node

• URL: http://arxiv.org/abs/2607.24907v2
• Date: Wed, 29 Jul 2026 06:48:41 GMT
• Title: Fault-tolerant distributed quantum computing with a single nucleus per node
• Abstract summary: In-node gates and measurements are cheap and high-fidelity, whereas inter-node communication relies on a low-coherence communication qubit and faulty photonics.<n>Previous approaches overcame the noisy link by placing several high-quality data qubits in each node and consuming them for Bell pair and GHZ state distillation.<n>Here we show that distillation can be avoided altogether.
• Score: 37.10575718385375
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Distributed quantum computing interconnects small, high-quality nodes through optical links, but this architecture carries a pronounced asymmetry: in-node gates and measurements are cheap and high-fidelity, whereas inter-node communication relies on a low-coherence communication qubit and faulty photonics. Previous approaches overcame the noisy link by placing several high-quality data qubits in each node and consuming them for Bell pair and GHZ state distillation. Here we show that distillation can be avoided altogether. The key observation is that we can engineer a communication error bias, where photonic Bell pairs suffer frequent phase errors but only rare bit-flip errors. We design the syndrome-extraction circuits so that this phase noise appears solely as a measurement error that does not propagate to the data qubits, and is therefore suppressed by simply repeating the measurement; letting the error-correcting code itself, rather than a dedicated distillation subroutine, to purify the link. This dramatically reduces the need for ancillary nuclei: Floquet codes require only a single data qubit per node, while general stabilizer codes require just one additional ancilla. We demonstrate high error-correction thresholds throughout this regime, and we identify lattice surgery as inherently robust for this setting, enabling logical operations at a threshold close to that of quantum memory. As a result, the performance of the quantum computer is limited by the high-quality data qubits, while the requirements on photon indistinguishability and coherence of the communication qubit are substantially relaxed.

Related papers

• The Gain-Engineered Transmon [68.89136228609398]
  We introduce and experimentally realize a noise-biased qubit in a standard transmon-readout resonator circuit.<n>Our results open a path towards using this system as a simple building-block for hardware-efficient quantum error detection and correction schemes.
  arXiv  Detail & Related papers  (2026-08-26T17:00:42Z)
• Simple loss-tolerant protocol for GHZ-state distribution in a quantum network [0.0]
  We propose a simple loss-tolerant protocol for the Greenberger-Horne-Zeilinger state distribution. Our protocol does not use quantum repeaters and is achievable with current quantum optics technology.
  arXiv  Detail & Related papers  (2024-04-30T11:16:37Z)
• Error Correlations in Photonic Qudit-Mediated Entanglement Generation [2.1587559138197667]
  We propose a qudit-mediated entangling protocol that completely circumvents the need for optical switches. We analyze the effect on entanglement purification algorithms and teleportation-based quantum error correction.
  arXiv  Detail & Related papers  (2023-12-03T22:25:21Z)
• Minimizing readout-induced noise for early fault-tolerant quantum computers [0.0]
  We present a different method for syndrome extraction, namely Generalized Syndrome Measurement. We can detect the error in the logical state with minimized readout-induced noise. We numerically analyze the performance of our protocol using Iceberg code and Steane code.
  arXiv  Detail & Related papers  (2023-04-23T04:16:26Z)
• Fault-tolerant Coding for Entanglement-Assisted Communication [46.0607942851373]
  This paper studies the study of fault-tolerant channel coding for quantum channels. We use techniques from fault-tolerant quantum computing to establish coding theorems for sending classical and quantum information in this scenario. We extend these methods to the case of entanglement-assisted communication, in particular proving that the fault-tolerant capacity approaches the usual capacity when the gate error approaches zero.
  arXiv  Detail & Related papers  (2022-10-06T14:09:16Z)
• Mid-circuit correction of correlated phase errors using an array of spectator qubits [0.30786914102688595]
  Scaling up invariably error-prone quantum processors is a formidable challenge. Recent proposals have suggested a complementary approach based on co-located, auxiliary'spectator' qubits. Here, we use an array of spectator qubits to correct correlated phase errors on an array of rubidium data qubits.
  arXiv  Detail & Related papers  (2022-08-24T18:00:05Z)
• Fault-tolerant parity readout on a shuttling-based trapped-ion quantum computer [64.47265213752996]
  We experimentally demonstrate a fault-tolerant weight-4 parity check measurement scheme. We achieve a flag-conditioned parity measurement single-shot fidelity of 93.2(2)%. The scheme is an essential building block in a broad class of stabilizer quantum error correction protocols.
  arXiv  Detail & Related papers  (2021-07-13T20:08:04Z)
• Hardware-Efficient, Fault-Tolerant Quantum Computation with Rydberg Atoms [55.41644538483948]
  We provide the first complete characterization of sources of error in a neutral-atom quantum computer. We develop a novel and distinctly efficient method to address the most important errors associated with the decay of atomic qubits to states outside of the computational subspace. Our protocols can be implemented in the near-term using state-of-the-art neutral atom platforms with qubits encoded in both alkali and alkaline-earth atoms.
  arXiv  Detail & Related papers  (2021-05-27T23:29:53Z)
• Crosstalk Suppression for Fault-tolerant Quantum Error Correction with Trapped Ions [62.997667081978825]
  We present a study of crosstalk errors in a quantum-computing architecture based on a single string of ions confined by a radio-frequency trap, and manipulated by individually-addressed laser beams. This type of errors affects spectator qubits that, ideally, should remain unaltered during the application of single- and two-qubit quantum gates addressed at a different set of active qubits. We microscopically model crosstalk errors from first principles and present a detailed study showing the importance of using a coherent vs incoherent error modelling and, moreover, discuss strategies to actively suppress this crosstalk at the gate level.
  arXiv  Detail & Related papers  (2020-12-21T14:20:40Z)
• Fault-tolerant Coding for Quantum Communication [71.206200318454]
  encode and decode circuits to reliably send messages over many uses of a noisy channel. For every quantum channel $T$ and every $eps>0$ there exists a threshold $p(epsilon,T)$ for the gate error probability below which rates larger than $C-epsilon$ are fault-tolerantly achievable. Our results are relevant in communication over large distances, and also on-chip, where distant parts of a quantum computer might need to communicate under higher levels of noise.
  arXiv  Detail & Related papers  (2020-09-15T15:10:50Z)

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.