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Related papers: Single-Qubit Gates Matter for Optimising Quantum C…

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We provide a method for compiling approximate multi-controlled single qubit gates into quantum circuits without ancilla qubits. The total number of elementary gates to decompose an n-qubit multi-controlled gate is proportional to 32n, and…

We consider a generic elementary gate sequence which is needed to implement a general quantum gate acting on n qubits -- a unitary transformation with 4^n degrees of freedom. For synthesizing the gate sequence, a method based on the…

Quantum Physics · Physics 2009-11-10 Mikko Mottonen , Juha J. Vartiainen , Ville Bergholm , Martti M. Salomaa

The initialization of quantum states or Quantum State Preparation (QSP) is a basic subroutine in quantum algorithms. In the worst case, general QSP algorithms are expensive due to the application of multi-controlled gates required to build…

In Noisy Intermediate-Scale Quantum (NISQ) era, quantum processing units (QPUs) suffer from, among others, highly limited connectivity between physical qubits. To make a quantum circuit effectively executable, a circuit transformation…

Quantum Physics · Physics 2022-01-26 Xiangzhen Zhou , Yuan Feng , Sanjiang Li

Some physical implementation schemes of quantum computing can apply two-qubit gates only on certain pairs of qubits. These connectivity constraints are commonly viewed as a significant disadvantage. For example, compiling an unrestricted…

Quantum Physics · Physics 2023-09-04 Pei Yuan , Jonathan Allcock , Shengyu Zhang

The number of superconducting qubits contained in a single quantum processor is increasing steadily. However, to realize a truly useful quantum computer, it is inevitable to increase the number of qubits much further by distributing quantum…

Quantum Physics · Physics 2024-09-23 Kazuki Koshino , Kunihiro Inomata

A CNOT circuit is the key gadget for entangling qubits in quantum computing systems. However, the qubit connectivity of noisy intermediate-scale quantum (NISQ) devices is constrained by their {limited connectivity architecture}. To improve…

Quantum Physics · Physics 2023-02-03 Bujiao Wu , Xiaoyu He , Shuai Yang , Lifu Shou , Guojing Tian , Jialin Zhang , Xiaoming Sun

We introduce AQCtensor, a novel algorithm to produce short-depth quantum circuits from Matrix Product States (MPS). Our approach is specifically tailored to the preparation of quantum states generated from the time evolution of quantum…

Quantum Physics · Physics 2025-06-23 Niall F. Robertson , Albert Akhriev , Jiri Vala , Sergiy Zhuk

Quantum algorithms promise quadratic or exponential speedups for applications in cryptography, chemistry and material sciences. The topologies of today's quantum computers offer limited connectivity, leading to significant overheads for…

Quantum Physics · Physics 2021-09-10 Sebastian Brandhofer , Hans Peter Büchler , Ilia Polian

As the effort to scale up existing quantum hardware proceeds, it becomes necessary to schedule quantum gates in a way that minimizes the number of operations. There are three constraints that have to be satisfied: the order or dependency of…

Quantum Physics · Physics 2018-08-28 Gian Giacomo Guerreschi , Jongsoo Park

Recent advancements in quantum computing have enabled practical use of quantum error detecting and correcting codes. However, current architectures and future proposals of quantum computer design suffer from limited qubit counts,…

Quantum Physics · Physics 2026-04-14 Cordell Mazzetti , Sayam Sethi , Rich Rines , Pranav Gokhale , Jonathan Mark Baker

A limited number of qubits, high error rates, and limited qubit connectivity are major challenges for effective near-term quantum computations. Quantum circuit partitioning divides a quantum computation into a set of computations that…

Quantum Physics · Physics 2023-08-21 Sebastian Brandhofer , Ilia Polian , Kevin Krsulich

Quantum circuits form a foundational framework in quantum science, enabling the description, analysis, and implementation of quantum computations. However, designing efficient circuits, typically constructed from single- and two-qubit…

Quantum Physics · Physics 2025-09-17 Yadong Wu , Pengfei Zhang , Ce Wang , Juan Yao , Yi-Zhuang You

Quantum algorithms need to be compiled to respect the constraints imposed by quantum processors, which is known as the mapping problem. The mapping procedure will result in an increase of the number of gates and of the circuit latency,…

Quantum Physics · Physics 2021-07-05 Lingling Lao , Hans van Someren , Imran Ashraf , Carmen G. Almudever

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

The design and architecture of a quantum instruction set are paramount to the performance of a quantum computer. This work introduces a gate scheme for qubits with $XX+YY$ coupling that directly and efficiently realizes any two-qubit gate…

Quantum Physics · Physics 2025-09-09 Jianxin Chen , Dawei Ding , Weiyuan Gong , Cupjin Huang , Qi Ye

Using the Parity Flow formalism, we show that physical SWAP gates can be eliminated in linear hardware architectures, without increasing the total number of two-qubit operations. This has a significant impact on the execution time of…

The ability to connect distant qubits plays a fundamental role in quantum computing. Therefore, quantum systems candidates for quantum computation must be able to interact all their constituent qubits. Here, we model the quantum dot spin…

Quantum Physics · Physics 2022-10-26 Iann Cunha , Leonardo Kleber Castelano

Analysis and verification of quantum circuits are highly challenging, given the exponential dependence of the number of states on the number of qubits. For analytical derivation, we propose a new quantum polynomial representation (QPR) to…

Quantum Physics · Physics 2025-03-14 Yu-Ting Kao , Hao-Yu Lu , Yeong-Jar Chang , Darsen Lu

Quantum computing hardware is affected by quantum noise that undermine the quality of results of an executed quantum program. Amongst other quantum noises, coherent error that caused by parameter drifting and miscalibration, remains…

Hardware Architecture · Computer Science 2024-10-15 Xiangyu Ren , Junjie Wan , Zhiding Liang , Antonio Barbalace