Analysis and Suppression of Errors in Quantum Random Access Memory under Extended Noise Models

• URL: http://arxiv.org/abs/2412.10318v2
• Date: Tue, 17 Dec 2024 18:20:35 GMT
• Title: Analysis and Suppression of Errors in Quantum Random Access Memory under Extended Noise Models
• Authors: Rohan Mehta, Gideon Lee, Liang Jiang,
• Abstract summary: We show that QRAM is highly resilient to arbitrary local incoherent noise channels. Fully quantifying the extent to which QRAM's noise resilience holds may provide a guide for the design of QRAM architectures.
• Score: 1.9545616531173555
• License:
• Abstract: Quantum random access memory (QRAM) is required for numerous quantum algorithms and network architectures. Previous work has shown that the ubiquitous bucket-brigade QRAM is highly resilient to arbitrary local incoherent noise channels occurring during the operation of the QRAM [PRX Quantum 2, 020311 (2021)], with query infidelities growing only polylogarithmically with memory width when errors are assumed to only occur on individual routers. We extend this result to a large class of generalized settings that arise in realistic situations, including arbitrary initialization errors, spatially correlated errors, as well as coherent errors, maintaining the polylogarithmic scaling in all instances. Fully quantifying the extent to which QRAM's noise resilience holds may provide a guide for the design of QRAM architectures - for instance, the resilience to initialization errors indicates that a reset protocol between successive queries may not be necessary. In the case of coherent errors, we find an up-to-quadratic increase in the infidelity bound, and therefore discuss generalizations to randomized compiling schemes, which usually are rendered inapplicable in the QRAM setting, to tailor these errors into more favorable stochastic noise.

Related papers

• Fault-Tolerant Belief Propagation for Practical Quantum Memory [6.322831694506286]
  A fault-tolerant approach to reliable quantum memory is essential for scalable quantum computing. We propose a decoder that utilizes a space-time Tanner graph across multiple rounds of syndrome extraction with mixed-alphabet error variables. Our simulations demonstrate high error thresholds of 0.4%-0.87% and strong error-floor performance for topological code families.
  arXiv  Detail & Related papers  (2024-09-27T12:21:45Z)
• Unified Architecture for a Quantum Lookup Table [1.0923877073891446]
  Quantum access to arbitrary classical data encoded in unitary black-box oracles underlies interesting data-intensive quantum algorithms. We present a general parameterized architecture for quantum circuits implementing a lookup table. Our architecture assumes only local 2D connectivity, yet recovers results that previously required all-to-all connectivity.
  arXiv  Detail & Related papers  (2024-06-26T02:54:02Z)
• Fidelity decay and error accumulation in random quantum circuits [0.3562485774739681]
  fidelity decays exponentially with both circuit depth and the number of qubits raised to an architecture-dependent power. We establish a robust linear relationship between fidelity and the heavy output frequency used in Quantum Volume tests to benchmark quantum processors.
  arXiv  Detail & Related papers  (2024-04-17T14:53:26Z)
• Fault-tolerant quantum architectures based on erasure qubits [49.227671756557946]
  We exploit the idea of erasure qubits, relying on an efficient conversion of the dominant noise into erasures at known locations. We propose and optimize QEC schemes based on erasure qubits and the recently-introduced Floquet codes. Our results demonstrate that, despite being slightly more complex, QEC schemes based on erasure qubits can significantly outperform standard approaches.
  arXiv  Detail & Related papers  (2023-12-21T17:40:18Z)
• Q-Pandora Unboxed: Characterizing Noise Resilience of Quantum Error Correction Codes [2.348041867134616]
  Quantum error correction codes (QECCs) are critical for realizing reliable quantum computing by protecting fragile quantum states against noise and errors. This paper conducts a comprehensive study analyzing two QECCs under different error types and noise models using simulations. rotated surface codes perform best with higher thresholds attributed to simplicity and lower qubit overhead.
  arXiv  Detail & Related papers  (2023-08-05T02:24:55Z)
• The Accuracy vs. Sampling Overhead Trade-off in Quantum Error Mitigation Using Monte Carlo-Based Channel Inversion [84.66087478797475]
  Quantum error mitigation (QEM) is a class of promising techniques for reducing the computational error of variational quantum algorithms. We consider a practical channel inversion strategy based on Monte Carlo sampling, which introduces additional computational error. We show that when the computational error is small compared to the dynamic range of the error-free results, it scales with the square root of the number of gates.
  arXiv  Detail & Related papers  (2022-01-20T00:05:01Z)
• Logical blocks for fault-tolerant topological quantum computation [55.41644538483948]
  We present a framework for universal fault-tolerant logic motivated by the need for platform-independent logical gate definitions. We explore novel schemes for universal logic that improve resource overheads. Motivated by the favorable logical error rates for boundaryless computation, we introduce a novel computational scheme.
  arXiv  Detail & Related papers  (2021-12-22T19:00:03Z)
• Error mitigation and quantum-assisted simulation in the error corrected regime [77.34726150561087]
  A standard approach to quantum computing is based on the idea of promoting a classically simulable and fault-tolerant set of operations. We show how the addition of noisy magic resources allows one to boost classical quasiprobability simulations of a quantum circuit.
  arXiv  Detail & Related papers  (2021-03-12T20:58:41Z)
• Sampling Overhead Analysis of Quantum Error Mitigation: Uncoded vs. Coded Systems [69.33243249411113]
  We show that Pauli errors incur the lowest sampling overhead among a large class of realistic quantum channels. We conceive a scheme amalgamating QEM with quantum channel coding, and analyse its sampling overhead reduction compared to pure QEM.
  arXiv  Detail & Related papers  (2020-12-15T15:51:27Z)
• Resilience of quantum random access memory to generic noise [2.5496329090462626]
  We study the effects of decoherence on Quantum Random Access Memory (QRAM) in full generality. Our proof identifies the origin of this noise resilience as the limited entanglement among the memory's components. We prove that high-fidelity queries are possible without quantum error correction.
  arXiv  Detail & Related papers  (2020-12-09T21:59:48Z)
• Parallelising the Queries in Bucket Brigade Quantum RAM [69.43216268165402]
  Quantum algorithms often use quantum RAMs (QRAM) for accessing information stored in a database-like manner. We show a systematic method to significantly reduce the effective query time by using Clifford+T gate parallelism. We conclude that, in theory, fault-tolerant bucket brigade quantum RAM queries can be performed approximately with the speed of classical RAM.
  arXiv  Detail & Related papers  (2020-02-21T14:50:03Z)

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.