English
Related papers

Related papers: Efficient Fourier-Based Linear Combination of Unit…

200 papers

We present a classically solvable model that leads to optimized low-depth quantum circuits leveraging separable pair approximations. The obtained circuits are well suited as a baseline circuit for emerging quantum hardware and can, in the…

Quantum Physics · Physics 2022-04-07 Jakob S. Kottmann , Alán Aspuru-Guzik

One of the challenges in quantum computing is the synthesis of unitary operators into quantum circuits with polylogarithmic gate complexity. Exact synthesis of generic unitaries requires an exponential number of gates in general. We propose…

Quantum Physics · Physics 2020-11-24 Daan Camps , Roel Van Beeumen

Quantum unitaries of the form $\Sigma_{c}\ket{c}\bra{c}\otimes U_{c}$ are ubiquitous in quantum algorithms. This class encompasses not only standard uniformly controlled gates (UCGs) but also a wide range of circuits with uniformly…

Quantum Physics · Physics 2025-12-11 Chengzhuo Xu , Xiao Chen , Xi Li , Zhihao Liu , Zhigang Li

To date, research in quantum computation promises potential for outperforming classical heuristics in combinatorial optimization. However, when aiming at provable optimality, one has to rely on classical exact methods like integer…

Quantum Physics · Physics 2025-03-13 Friedrich Wagner , Jonas Nüßlein , Frauke Liers

Unitary decomposition is a widely used method to map quantum algorithms to an arbitrary set of quantum gates. Efficient implementation of this decomposition allows for translation of bigger unitary gates into elementary quantum operations,…

Quantum Physics · Physics 2024-03-14 A. M. Krol , A. Sarkar , I. Ashraf , Z. Al-Ars , K. Bertels

Block encoding is a successful technique used in several powerful quantum algorithms. In this work we provide an explicit quantum circuit for block encoding a sparse matrix with a periodic diagonal structure. The proposed methodology is…

Near-term hardware is constrained by high error rates, small qubit counts, and relatively low output fidelity, making the execution of large, high performance quantum circuits difficult. Circuit partitioning (or circuit cutting) has emerged…

Quantum Physics · Physics 2026-04-27 Connor Howe , Cristina Radian , Justin Woodring , Vardaan Sahgal , Brian J. McDermott

The recent advent of commercially available quantum annealing hardware (QAH) has expanded opportunities for research into quantum annealing-based algorithms. In the domain of power systems, this advancement has driven increased interest in…

Optimization and Control · Mathematics 2025-03-26 Rosemary Barrass , Harsha Nagarajan , Carleton Coffrin

The Quantum Approximate Optimization Algorithm (QAOA) is a promising approach for programming a near-term gate-based hybrid quantum computer to find good approximate solutions of hard combinatorial problems. However, little is currently…

Quantum Physics · Physics 2018-11-21 Gavin E. Crooks

Combinatorial optimization is a promising application for near-term quantum computers, however, identifying performant algorithms suited to noisy quantum hardware remains as an important goal to potentially realizing quantum computational…

Quantum Physics · Physics 2025-04-01 Titus D. Morris , Ananth Kaushik , Martin Roetteler , Phillip C. Lotshaw

We give three new algorithms for efficient in-place estimation, without using ancilla qubits, of average fidelity of a quantum logic gate acting on a d-dimensional system using much fewer random bits than what was known so far. Previous…

Quantum Physics · Physics 2019-01-23 Aditya Nema , Pranab Sen

Gate model quantum computers with too many qubits to be simulated by available classical computers are about to arrive. We present a strategy for programming these devices without error correction or compilation. This means that the number…

Quantum Physics · Physics 2017-03-21 E. Farhi , J. Goldstone , S. Gutmann , H. Neven

Vast numbers of qubits will be needed for large-scale quantum computing due to the overheads associated with error correction. We present a scheme for low-overhead fault-tolerant quantum computation based on quantum low-density parity-check…

Quantum Physics · Physics 2022-05-24 Lawrence Z. Cohen , Isaac H. Kim , Stephen D. Bartlett , Benjamin J. Brown

Quantum error-correcting codes protect fragile quantum information by encoding it redundantly, but identifying codes that perform well in practice with minimal overhead remains difficult due to the combinatorial search space and the high…

Quantum Physics · Physics 2026-01-27 Yihua Chengyu , Richard Meister , Conor Carty , Sheng-Ku Lin , Roberto Bondesan

Any square matrix can be transformed into a doubly stochastic matrix via Sinkhorn scaling with diagonal matrices or completing to a larger dimensional matrix. Standard Birkhoff-von Neumann and Pauli decompositions represent such matrices as…

Quantum Physics · Physics 2026-05-28 Ammar Daskin

We introduce a family of identities that express general linear non-unitary evolution operators as a linear combination of unitary evolution operators, each solving a Hamiltonian simulation problem. This formulation can exponentially…

Quantum Physics · Physics 2025-12-16 Dong An , Andrew M. Childs , Lin Lin

The union-find decoder is a leading algorithmic approach to the correction of quantum errors on the surface code, achieving code thresholds comparable to minimum-weight perfect matching (MWPM) with amortised computational time scaling…

Quantum Physics · Physics 2025-04-10 Sam J. Griffiths , Dan E. Browne

The prospect of using quantum computers to solve combinatorial optimization problems via the quantum approximate optimization algorithm (QAOA) has attracted considerable interest in recent years. However, a key limitation associated with…

Quantum Physics · Physics 2023-01-05 Alicia B. Magann , Kenneth M. Rudinger , Matthew D. Grace , Mohan Sarovar

Quantum circuit optimization - the process of transforming a quantum circuit into an equivalent one with reduced time and space requirements - is crucial for maximizing the utility of current and near-future quantum devices. While most…

Quantum Physics · Physics 2026-01-23 Marcin Szyniszewski , Aleks Kissinger , Noah Linden , Paul Skrzypczyk

Quantum error correction is an important ingredient for scalable quantum computing. Stabilizer codes are one of the most promising and straightforward ways to correct quantum errors, are convenient for logical operations, and improve…

Quantum Physics · Physics 2025-02-07 Ilya. A. Simakov , Ilya. S. Besedin