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Related papers: Query and Depth Upper Bounds for Quantum Unitaries…

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Grover's algorithm, orginally conceived as a means of searching an unordered database, can also be used to extract solutions from the result sets generated by quantum computations. The Grover algorithm exploits the concept of an oracle…

Quantum Physics · Physics 2024-11-19 Fintan M. Bolton

A locally decodable code encodes n-bit strings x in m-bit codewords C(x), in such a way that one can recover any bit x_i from a corrupted codeword by querying only a few bits of that word. We use a quantum argument to prove that LDCs with 2…

Quantum Physics · Physics 2007-05-23 Iordanis Kerenidis , Ronald de Wolf

We show that any quantum circuit of treewidth $t$, built from $r$-qubit gates, requires at least $\Omega(\frac{n^{2}}{2^{O(r\cdot t)}\cdot \log^4 n})$ gates to compute the element distinctness function. Our result generalizes a…

Computational Complexity · Computer Science 2016-10-03 Mateus de Oliveira Oliveira

We present quantum circuits to implement an exhaustive key search for the Advanced Encryption Standard (AES) and analyze the quantum resources required to carry out such an attack. We consider the overall circuit size, the number of qubits,…

Quantum Physics · Physics 2015-12-17 Markus Grassl , Brandon Langenberg , Martin Roetteler , Rainer Steinwandt

Parallel computation enables multiple processors to execute different parts of a task simultaneously, improving processing speed and efficiency. In quantum computing, parallel gate implementation involves executing gates independently in…

Quantum Physics · Physics 2024-11-20 Boris Arseniev

We propose and analyze a nonunitary variant of the continuous time Grover search algorithm based on frequent Zeno-type measurements. We show that the algorithm scales similarly to the pure quantum version by deriving tight analytical lower…

Quantum Physics · Physics 2022-11-08 P. V. Pyshkin , A. Gábris , Da-Wei Luo , Jian-Qiang You , Lian-Ao Wu

We design a circuit structure with linear depth to implement an $n$-qubit Toffoli gate. The proposed construction uses a quadratic-size circuit consists of elementary 2-qubit controlled-rotation gates around the x axis and uses no ancilla…

Quantum Physics · Physics 2015-06-15 Mehdi Saeedi , Massoud Pedram

We focus on the depth optimization of CNOT circuits on hardwares with limited connectivity. We adapt the algorithm from Kutin et al. that implements any $n$-qubit CNOT circuit in depth at most $5n$ on a Linear Nearest Neighbour (LNN)…

Quantum Physics · Physics 2023-03-14 Timothée Goubault de Brugière , Simon Martiel

We consider the Unitary Permutation problem which consists, given $n$ unitary gates $U_1, \ldots, U_n$ and a permutation $\sigma$ of $\{1,\ldots, n\}$, in applying the unitary gates in the order specified by $\sigma$, i.e. in performing…

Quantum Physics · Physics 2016-10-11 Stefano Facchini , Simon Perdrix

While implementing a quantum algorithm it is crucial to reduce the quantum resources, in order to obtain the desired computational advantage. For most fault-tolerant quantum error-correcting codes the cost of implementing the non-Clifford…

Quantum Physics · Physics 2023-02-10 Vlad Gheorghiu , Michele Mosca , Priyanka Mukhopadhyay

Unitary and non-unitary diagonal operators are fundamental building blocks in quantum algorithms with applications in the resolution of partial differential equations, Hamiltonian simulations, the loading of classical data on quantum…

Quantum Physics · Physics 2025-01-22 Julien Zylberman , Ugo Nzongani , Andrea Simonetto , Fabrice Debbasch

We introduce a novel deterministic quantum search algorithm that provides a practical alternative to conventional probabilistic search approaches. Our scheme eliminates the inherent uncertainty of quantum search without relying on arbitrary…

Quantum Physics · Physics 2025-07-22 John Burke , Ciaran McGoldrick

Quantum access to arbitrary classical data encoded in unitary black-box oracles underlies interesting data-intensive quantum algorithms, such as machine learning or electronic structure simulation. The feasibility of these applications…

Quantum Physics · Physics 2025-12-23 Shuchen Zhu , Aarthi Sundaram , Guang Hao Low

This work tests the performance of Grover's search circuits on some IBM superconducting quantum devices in case of the size of search space $N=2^4$ and $N=2^5$. Ideally, we expect to get an outcome probability distribution that is clearly…

Quantum Physics · Physics 2023-08-08 Yunos El Kaderi , Andreas Honecker , Iryna Andriyanova

Quantum contextuality is a limitation on deterministic hidden variable models, testable in measurement scenarios where outcomes differ under quantum or classical descriptions due to a common set of constraints. When considering measurements…

Quantum Physics · Physics 2025-09-25 Colm Kelleher , Frédéric Holweck

We show that almost all n-bit Boolean functions have bounded-error quantum query complexity at least n/2, up to lower-order terms. This improves over an earlier n/4 lower bound of Ambainis, and shows that van Dam's oracle interrogation is…

Quantum Physics · Physics 2012-08-07 Andris Ambainis , Arturs Backurs , Juris Smotrovs , Ronald de Wolf

The field of linear optical quantum computation (LOQC) will soon need a repertoire of experimental milestones. We make progress in this direction by describing several experiments based on Grover's algorithm. These experiments range from a…

Quantum Physics · Physics 2009-11-10 Jennifer L. Dodd , Timothy C. Ralph , G. J. Milburn

We derive a rigorous upper bound on the classical computation time of finite-ranged tensor network contractions in $d \geq 2$ dimensions. Consequently, we show that quantum circuits of single-qubit and finite-ranged two-qubit gates can be…

Quantum Physics · Physics 2023-11-07 Thorsten B. Wahl , Sergii Strelchuk

Adaptive quantum circuits employ unitary gates assisted by mid-circuit measurement, classical computation on the measurement outcome, and the conditional application of future unitary gates based on the result of the classical computation.…

Quantum search is among the most important algorithms in quantum computing. At its core is quantum amplitude amplification, a technique that achieves a quadratic speedup over classical search by combining two global reflections: the oracle,…

Quantum Physics · Physics 2026-05-05 John Burke , Ciaran McGoldrick
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