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Related papers: A Precise Error Bound for Quantum Phase Estimation

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Quantum computing hardware has grown sufficiently complex that it often can no longer be simulated by classical computers, but its computational power remains limited by errors. These errors corrupt the results of quantum algorithms, and it…

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

We propose a scheme for translating metrological precision bounds into lower bounds on query complexity of quantum search algorithms. Within the scheme the link between quadratic performance enhancement in idealized quantum metrological and…

Quantum Physics · Physics 2016-10-13 Rafal Demkowicz-Dobrzanski , Marcin Markiewicz

It is imperative that useful quantum computers be very difficult to simulate classically; otherwise classical computers could be used for the applications envisioned for the quantum ones. Perfect quantum computers are unarguably…

Quantum Physics · Physics 2020-11-26 Yiqing Zhou , E. Miles Stoudenmire , Xavier Waintal

Quantum metrology can achieve far better precision than classical metrology, and is one of the most important applications of quantum technologies in the real world. To attain the highest precision promised by quantum metrology, all steps…

Quantum Physics · Physics 2021-12-17 Jing Liu , Mao Zhang , Hongzhen Chen , Lingna Wang , Haidong Yuan

The schemes for fault-tolerant postselected quantum computation given in [Knill, Fault-Tolerant Postselected Quantum Computation: Schemes, http://arxiv.org/abs/quant-ph/0402171] are analyzed to determine their error-tolerance. The analysis…

Quantum Physics · Physics 2007-05-23 E. Knill

Approximation errors must be taken into account when compiling quantum programs into a low-level gate set. We present a methodology that tracks such errors automatically and then optimizes accuracy parameters to guarantee a specified…

Quantum Physics · Physics 2021-01-06 Giulia Meuli , Mathias Soeken , Martin Roetteler , Thomas Häner

We provide a new quantum algorithm that efficiently determines the quality of a least-squares fit over an exponentially large data set by building upon an algorithm for solving systems of linear equations efficiently (Harrow et al., Phys.…

Quantum Physics · Physics 2013-01-10 Nathan Wiebe , Daniel Braun , Seth Lloyd

Threshold theorems for fault-tolerant quantum computing assume that errors are of certain types. But how would one detect whether errors of the "wrong" type occur in one's experiment, especially if one does not even know what type of error…

Quantum Physics · Physics 2015-06-16 Lucia Schwarz , Steven van Enk

We extend the concept of probabilistic unambiguous discrimination of quantum states to quantum state estimation. We consider a scenario where the measurement device can output either an estimate of the unknown input state or an inconclusive…

Quantum Physics · Physics 2009-11-13 Jaromir Fiurasek

For the first time in history, we are seeing a branching point in computing paradigms with the emergence of quantum processing units (QPUs). Extracting the full potential of computation and realizing quantum algorithms with a…

Quantum Physics · Physics 2022-11-29 Sergey Bravyi , Oliver Dial , Jay M. Gambetta , Dario Gil , Zaira Nazario

We consider the probability by which quantum phase measurements of a given precision can be done successfully. The least upper bound of this probability is derived and the associated optimal state vectors are determined. The probability…

Quantum Physics · Physics 2009-02-14 Thomas Schürmann

The outcomes of quantum mechanical experiments are inherently random. It is therefore necessary to develop stringent methods for quantifying the degree of statistical uncertainty about the results of quantum experiments. For the…

Quantum Physics · Physics 2017-10-11 Daniel Suess , Łukasz Rudnicki , Thiago O. Maciel , David Gross

Quantum computers use the quantum interference of different computational paths to enhance correct outcomes and suppress erroneous outcomes of computations. A common pattern underpinning quantum algorithms can be identified when quantum…

Quantum Physics · Physics 2009-10-30 Richard Cleve , Artur Ekert , Chiara Macchiavello , Michele Mosca

Current techniques in quantum process tomography typically return a single point estimate of an unknown process based on a finite albeit large amount of measurement data. Due to statistical fluctuations, however, other processes close to…

Quantum Physics · Physics 2019-05-15 Le Phuc Thinh , Philippe Faist , Jonas Helsen , David Elkouss , Stephanie Wehner

Quantum measurements, alongside quantum states and processes, form a cornerstone of quantum information processing. However, unlike states and processes, their efficient characterisation remains relatively unexplored. We resolve this…

A reliable method for characterizing quantum operations that is suitable for improving and validating their accuracies is indispensable for realizing a practical quantum computer. Known methods are still not sufficient because they lack…

Quantum Physics · Physics 2021-06-25 Takanori Sugiyama , Shinpei Imori , Fuyuhiko Tanaka

The purpose of this little survey is to give a simple description of the main approaches to quantum error correction and quantum fault-tolerance. Our goal is to convey the necessary intuitions both for the problems and their solutions in…

Quantum Physics · Physics 2007-05-23 Julia Kempe

Quantum computers hold the promise of solving computational problems which are intractable using conventional methods. For fault-tolerant operation quantum computers must correct errors occurring due to unavoidable decoherence and limited…

Quantum phase estimation algorithm (PEA) is one of the most important algorithms in early studies of quantum computation. It is also a key for many other quantum algorithms, such as the quantum counting algorithm and the Shor's integer…

Quantum Physics · Physics 2022-10-04 Xi Lu , Hongwei Lin