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Related papers: Fault-Tolerant Quantum Walks

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There are few known exponential speedups for quantum algorithms and these tend to fall into even fewer families. One speedup that has mostly resisted generalization is the use of quantum walks to traverse the welded-tree graph, due to…

Quantum Physics · Physics 2026-01-21 Shankar Balasubramanian , Tongyang Li , Aram Harrow

Quantum error correction is a crucial tool for mitigating hardware errors in quantum computers by encoding logical information into multiple physical qubits. However, no single error-correcting code allows for an intrinsically…

We present a method of concatenated quantum error correction in which improved classical processing is used with existing quantum codes and fault-tolerant circuits to more reliably correct errors. Rather than correcting each level of a…

Quantum Physics · Physics 2012-10-26 Zachary W. E. Evans , Ashley M. Stephens

Quantum error correction is necessary to perform large-scale quantum computations in the presence of noise and decoherence. As a result, several aspects of quantum error correction have already been explored. These have been primarily…

Quantum Physics · Physics 2021-08-05 Ariel Shlosberg , Anthony M. Polloreno , Graeme Smith

In quantum engineering, faults may occur in a quantum control system, which will cause the quantum control system unstable or deteriorate other relevant performance of the system. This note presents an estimator-based fault-tolerant control…

Systems and Control · Computer Science 2018-06-13 Shi Wang , Daoyi Dong

The implementation of fault-tolerant quantum gates on encoded logic qubits is considered. It is shown that transversal implementation of logic gates based on simple geometric control ideas is problematic for realistic physical systems…

Quantum Physics · Physics 2009-10-30 R. Nigmatullin , S. G. Schirmer

We introduce an analytically treatable spin decoherence model for quantum walk on a line that yields the exact position probability distribution of an unbiased classical random walk at all-time scales. This spin decoherence model depicts a…

Quantum Physics · Physics 2018-09-05 Mahesh N. Jayakody , Asiri Nanayakkara

The interest in quantum walks has been steadily increasing during the last two decades. It is still worth to present new forms of quantum walks that might find practical applications and new physical behaviors. In this work, we define…

Quantum Physics · Physics 2020-04-06 Bruno Chagas , Renato Portugal

Quantum walks on graphs can model physical processes and serve as efficient tools in quantum information theory. Once we admit random variations in the connectivity of the underlying graph, we arrive at the problem of percolation, where the…

Quantum Physics · Physics 2014-02-12 Bálint Kollár , Jaroslav Novotný , Tamás Kiss , Igor Jex

In this paper, a study on discrete-time coined quantum walks on the line is presented. Clear mathematical foundations are still lacking for this quantum walk model. As a step towards this objective, the following question is being…

Quantum Physics · Physics 2013-01-01 Marcos Villagra , Masaki Nakanishi , Shigeru Yamashita , Yasuhiko Nakashima

Quantum walks (QWs) represent pillars of quantum dynamics and information processing. They provide a powerful framework for simulating quantum transport, designing search algorithms, and enabling universal quantum computation. Several…

Quantum Physics · Physics 2026-01-30 E. Stefanutti , J. Philipps , J. Buetow , A. Guidara , M. Nuvoli , A. Chiuri , L. Sansoni

In recent years, quantum walks have been widely researched and have shown exciting properties. One such is a quadratic speed-up in hitting time compared to its classical counterpart. In this paper, we design a quantum circuit for the MNRS…

Quantum Physics · Physics 2021-08-06 Ellinor Wanzambi , Stina Andersson

Quantum walks provide a natural framework to approach graph problems with quantum computers, exhibiting speedups over their classical counterparts for tasks such as the search for marked nodes or the prediction of missing links.…

Quantum Physics · Physics 2023-06-27 Duarte Magano , João Moutinho , Bruno Coutinho

We investigate quantum walks in multiple dimensions with different quantum coins. We augment the model by assuming that at each step the amplitudes of the coin state are multiplied by random phases. This model enables us to study in detail…

Quantum Physics · Physics 2009-11-13 Jozef Kosik , Vladimir Buzek , Mark Hillery

A quantum walk places a traverser into a superposition of both graph location and traversal "spin." The walk is defined by an initial condition, an evolution determined by a unitary coin/shift-operator, and a measurement based on the…

Quantum Physics · Physics 2015-11-25 Marko A. Rodriguez , Jennifer H. Watkins

Fault-tolerant quantum computation critically depends on architectures uniting high encoding rates with physical implementability. Quantum low-density parity-check (qLDPC) codes, including bivariate bicycle (BB) codes, achieve dramatic…

Quantum Physics · Physics 2025-06-24 Yingli Yang , Guo Zhang , Ying Li

Holonomic quantum computation exploits a quantum state's non-trivial, matrix-valued geometric phase (holonomy) to perform fault-tolerant computation. Holonomies arising from systems where the Hamiltonian traces a continuous path through…

Quantum Physics · Physics 2022-02-08 Cornelis J. G. Mommers , Erik Sjöqvist

Reliable qubits are difficult to engineer, but standard fault-tolerance schemes use seven or more physical qubits to encode each logical qubit, with still more qubits required for error correction. The large overhead makes it hard to…

Quantum Physics · Physics 2018-11-02 Rui Chao , Ben W. Reichardt

The Quantum Computer Condition (QCC) provides a rigorous and completely general framework for carrying out analyses of questions pertaining to fault-tolerance in quantum computers. In this paper we apply the QCC to the problem of…

Quantum Physics · Physics 2007-05-23 Gerald Gilbert , Michael Hamrick , F. Javier Thayer , Yaakov S. Weinstein

Logical qubits can be protected from decoherence by performing QEC cycles repeatedly. Algorithms for fault-tolerant QEC must be compiled to the specific hardware platform under consideration in order to practically realize a quantum memory…

Quantum Physics · Physics 2025-05-13 Sascha Heußen , David F. Locher , Markus Müller