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Related papers: Unitary Averaging with Fault and Loss Tolerance

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Quantum error correction works effectively only if the error rate of gate operations is sufficiently low. However, some rare physical mechanisms can cause a temporary increase in the error rate that affects many qubits; examples include…

Quantum Physics · Physics 2024-06-28 Shi Jie Samuel Tan , Christopher A. Pattison , Matt McEwen , John Preskill

Quantum error correction requires the detection of errors by reliable measurements of suitable multi-qubit correlation operators. Here, we experimentally demonstrate a fault-tolerant weight-4 parity check measurement scheme. An additional…

Quantum error correction and fault-tolerance make it possible to perform quantum computations in the presence of imprecision and imperfections of realistic devices. An important question is to find the noise rate at which errors can be…

Quantum Physics · Physics 2016-06-30 Christopher Chamberland , Tomas Jochym-O'Connor , Raymond Laflamme

Proving threshold theorems for fault-tolerant quantum computation is a burdensome endeavor with many moving parts that come together in relatively formulaic but lengthy ways. It is difficult and rare to combine elements from multiple papers…

Quantum Physics · Physics 2025-08-15 Zhiyang He , Quynh T. Nguyen , Christopher A. Pattison

An additive noise channel is considered, in which the distribution of the noise is nonparametric and unknown. The problem of learning encoders and decoders based on noise samples is considered. For uncoded communication systems, the problem…

Information Theory · Computer Science 2021-11-17 Nir Weinberger

Error correcting codes with a universal set of transversal gates are a desideratum for quantum computing. Such codes, however, are ruled out by the Eastin-Knill theorem. Moreover, the theorem also rules out codes which are covariant with…

Quantum Physics · Physics 2022-06-22 Yuxiang Yang , Yin Mo , Joseph M. Renes , Giulio Chiribella , Mischa P. Woods

We have previously (quant-ph/9608012) shown that for quantum memories and quantum communication, a state can be transmitted over arbitrary distances with error $\epsilon$ provided each gate has error at most $c\epsilon$. We discuss a…

Quantum Physics · Physics 2008-02-03 E. Knill , R. Laflamme , W. Zurek

Many quantum operations are expected to exhibit bias in the structure of their errors. Recent works have shown that a fixed bias can be exploited to improve error tolerance by statically arranging the errors in beneficial configurations. In…

Quantum Physics · Physics 2023-03-29 Hector Bombín , Chris Dawson , Naomi Nickerson , Mihir Pant , Jordan Sullivan

We present a simple method for constructing optimal fault-tolerant approximations of arbitrary unitary gates using an arbitrary discrete universal gate set. The method presented is numerical and scales exponentially with the number of gates…

Quantum Physics · Physics 2011-08-25 Austin G. Fowler

Estimates of the quantum accuracy threshold often tacitly assume that it is possible to interact arbitrary pairs of qubits in a quantum computer with a failure rate that is independent of the distance between them. None of the many physical…

Quantum Physics · Physics 2013-05-29 A. M. Stephens , Z. W. E. Evans

Various quantum applications can be reduced to estimating expectation values, which are inevitably deviated by operational and environmental errors. Although errors can be tackled by quantum error correction, the overheads are far from…

Quantum Physics · Physics 2020-02-19 Shuaining Zhang , Yao Lu , Kuan Zhang , Wentao Chen , Ying Li , Jing-Ning Zhang , Kihwan Kim

Robust gate sequences are widely used to reduce the sensitivity of gate operations to experimental imperfections. Typically, the optimization minimizes the average gate error, however, recent work in quantum error correction has…

Quantum Physics · Physics 2023-10-31 Sven Jandura , Jeff D Thompson , Guido Pupillo

Detectability of failures of linear programming (LP) decoding and the potential for improvement by adding new constraints motivate the use of an adaptive approach in selecting the constraints for the underlying LP problem. In this paper, we…

Information Theory · Computer Science 2007-07-13 Mohammad H. Taghavi , Paul H. Siegel

Fault-tolerant operations based on stabilizer codes are the state of the art in suppressing error rates in quantum computations. Most such codes do not permit a straightforward implementation of non-Clifford logical operations, which are…

Fault-tolerant quantum computing will require accurate estimates of the resource overhead, but standard metrics such as gate fidelity and diamond distance have been shown to be poor predictors of logical performance. We present a scalable…

Quantum Physics · Physics 2023-01-26 Pavithran Iyer , Aditya Jain , Stephen D. Bartlett , Joseph Emerson

In general, fault-tolerant quantum error correction (FTQEC) procedures are designed to detect, correct, and be fault-tolerant against errors occurring within the qubit subspace. But in some qubit implementations, additional "leakage" errors…

Quantum Physics · Physics 2014-05-09 Ben Fortescue , Sameer Nawaf , Mark Byrd

We show how phase and amplitude estimation algorithms can be parallelized. This can reduce the gate depth of the quantum circuits to that of a single Grover operator with a small overhead. Further, we show that for quantum amplitude…

Quantum Physics · Physics 2022-12-19 M. C. Braun , T. Decker , N. Hegemann , S. F. Kerstan

Using tools developed in a recent work by Shen and the second author, in this paper we carry out an in-depth study on the average decoding error probability of the random matrix ensemble over the erasure channel under three decoding…

Information Theory · Computer Science 2024-04-23 Chin Hei Chan , Fang-Wei Fu , Maosheng Xiong

Decoders that provide an estimate of the probability of a logical failure conditioned on the error syndrome ("soft-output decoders") can reduce the overhead cost of fault-tolerant quantum memory and computation. In this work, we construct…

Quantum Physics · Physics 2024-06-04 Nadine Meister , Christopher A. Pattison , John Preskill

In order to solve the problem of non-ideal training sets (i.e., the less-complete or over-complete sets) and implement one-iteration learning, a novel efficient quantum perceptron algorithm based on unitary weights is proposed, where the…

Quantum Physics · Physics 2024-05-14 Wenjie Liu , Peipei Gao , Yuxiang Wang , Wenbin Yu , Maojun Zhang