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It has previously been established that the logarithmic-depth approximate quantum Fourier transform (AQFT) provides a suitable replacement for the regular QFT in many quantum algorithms. Since the AQFT is less accurate by definition,…

Quantum Physics · Physics 2007-05-23 Donny Cheung

Quantum simulation is a cornerstone application for quantum computing, yet standard methods face a trade-off between circuit depth and accuracy: Trotterization depth scales with the number of Hamiltonian terms $L$, while sampling-based…

Quantum Physics · Physics 2026-05-01 Sangjin Lee , Sangkook Choi

We present a novel application of the HHL (Harrow-Hassidim-Lloyd) algorithm -- a quantum algorithm solving systems of linear equations -- in solving an open problem about quantum random walks, namely computing hitting (or absorption)…

Quantum Physics · Physics 2022-09-13 Ji Guan , Qisheng Wang , Mingsheng Ying

We introduce two variations of the quantum phase estimation algorithm: quantum shifted phase estimation and quantum punctured phase estimation. The shifted method employs a bit-string left shift to discard the most significant bit and focus…

Quantum Physics · Physics 2025-12-11 Yonghae Lee , Minjin Choi , Youngho Min , Eunok Bae , Sunghyun Bae

We study the average case approximation of the Boolean mean by quantum algorithms. We prove general query lower bounds for classes of probability measures on the set of inputs. We pay special attention to two probabilities, where we show…

Quantum Physics · Physics 2007-05-23 A. Papageorgiou

Practical quantum computing applications to power grids are nonexistent at the moment. This paper investigates how a fundamental grid problem, namely DC power flow, can be solved using quantum computing. Power flow is the most widely used…

Quantum Physics · Physics 2021-06-29 Rozhin Eskandarpour , Kumar Ghosh , Amin Khodaei , Aleksi Paaso

Solving linear systems of equations is an important problem in science and engineering. Many quantum algorithms, such as the Harrow-Hassidim-Lloyd (HHL) algorithm (for quantum-gate computers) and the box algorithm (for quantum-annealing…

Computational Engineering, Finance, and Science · Computer Science 2024-05-07 Sanjay Suresh , Krishnan Suresh

The Poisson equation has many applications across the broad areas of science and engineering. Most quantum algorithms for the Poisson solver presented so far, either suffer from lack of accuracy and/or are limited to very small sizes of the…

Quantum Physics · Physics 2022-09-23 Walter Robson , Kamal K. Saha , Connor Howington , In-Saeng Suh , Jaroslaw Nabrzyski

In this paper, we model and solve a fundamental power system problem, i.e., DC power flow, using a practical quantum computer. The Harrow-Hassidim-Lloyd (HHL) quantum algorithm is used to solve the DC power flow problem. The HHL algorithm…

Quantum Physics · Physics 2020-10-07 Rozhin Eskandarpour , Kumar Ghosh , Amin Khodaei , Liuxi Zhang , Aleksi Paaso , Shay Bahramirad

Binary Neural Networks are a promising technique for implementing efficient deep models with reduced storage and computational requirements. The training of these is however, still a compute-intensive problem that grows drastically with the…

The Quantum Fourier Transformation (QFT) is a well-known subroutine for algorithms on qubit-based universal quantum computers. In this work, the known QFT circuit is used to derive an efficient circuit for the multidimensional QFT. The…

Quantum Physics · Physics 2023-02-01 Philipp Pfeffer

Quantum computing enables the efficient resolution of complex problems, often outperforming classical methods across various applications. In 2009, Harrow, Hassidim and Lloyd proposed an algorithm for solving linear systems of equations,…

Computational Fluid Dynamics simulations are crucial in industrial applications but require extensive computational resources, particularly for extreme turbulent regimes. While classical digital approaches remain the standard, quantum…

Quantum Physics · Physics 2025-04-18 Francesco Turro , Alessandra Lignarolo , Daniele Dragoni

Quantum Fourier transform (QFT) is a key function to realize quantum computers. A QFT followed by measurement was demonstrated on a simple circuit based on fiber-optics. The QFT was shown to be robust against imperfections in the rotation…

Quantum Physics · Physics 2007-05-23 Akihisa Tomita , Kazuo Nakamura

This paper proposes a class of power-of-two FFT (Fast Fourier Transform) algorithms, called AM-QFT algorithms, that contains the improved QFT (Quick Fourier Transform), an algorithm recently published, as a special case. The main idea is to…

Data Structures and Algorithms · Computer Science 2014-04-08 Lorenzo Pasquini

The overheads of classical decoding for quantum error correction on superconducting quantum systems grow rapidly with the number of logical qubits and their correction code distance. Decoding at room temperature is bottle-necked by…

The quantum Fourier transform (QFT) plays an important role in many known quantum algorithms such as Shor's algorithm for prime factorisation. In this paper we show that the QFT algorithm can, on a restricted set of input states, be…

Quantum Physics · Physics 2020-01-27 Alastair A. Abbott

The algorithmic error of digital quantum simulations is usually explored in terms of the spectral norm distance between the actual and ideal evolution operators. In practice, this worst-case error analysis may be unnecessarily pessimistic.…

Quantum Physics · Physics 2023-02-02 Qi Zhao , You Zhou , Alexander F. Shaw , Tongyang Li , Andrew M. Childs

The Schrieffer-Wolff transformation aims to solve degenerate perturbation problems and give an effective Hamiltonian that describes the low-energy dynamics of the exact Hamiltonian in the low-energy subspace of unperturbed Hamiltonian. This…

Quantum Physics · Physics 2022-10-13 Zongkang Zhang , Yongdan Yang , Xiaosi Xu , Ying Li

The standard circuit model for quantum computation presumes the ability to directly perform gates between arbitrary pairs of qubits, which is unlikely to be practical for large-scale experiments. Power-law interactions with strength…