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Related papers: Low-depth Quantum Circuit Decomposition of Multi-c…

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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

Current noisy intermediate-scale quantum (NISQ) devices can only execute small circuits with shallow depth, as they are still constrained by the presence of noise: quantum gates have error rates and quantum states are fragile due to…

Quantum Physics · Physics 2024-06-11 Shihao Zhang , Kai Huang , Lvzhou Li

In this paper, we explore multilevel circuit optimization (MLCO), where we deploy multiple gate sets and progressively lower the source circuit through the gate sets to the target circuit. At each level, we first perform an appropriate set…

Quantum Physics · Physics 2025-05-19 Tamiya Onodera , Yuki Sato , Toshinari Itoko , Naoki Yamamoto

Quantum algorithms on near-term quantum processors are typically executed using shallow quantum circuits composed of one- and two-qubit gates. However, as circuit depth and gate number increase, gate imperfections and qubit decoherence…

Quantum circuits currently constitute a dominant model for quantum computation. Our work addresses the problem of constructing quantum circuits to implement an arbitrary given quantum computation, in the special case of two qubits. We…

Quantum Physics · Physics 2009-11-07 Stephen S. Bullock , Igor L. Markov

The depth of quantum circuits is a critical factor when running them on state-of-the-art quantum devices due to their limited coherence times. Reducing circuit depth decreases noise in near-term quantum computations and reduces overall…

Quantum Physics · Physics 2025-05-08 Elisa Bäumer , Stefan Woerner

The three-input TOFFOLI gate is the workhorse of circuit synthesis for classical logic operations on quantum data, e.g., reversible arithmetic circuits. In physical implementations, however, TOFFOLI gates are decomposed into six CNOT gates…

Quantum Physics · Physics 2011-11-03 Vivek V. Shende , Igor L. Markov

In this note we present explicit canonical forms for all the elements in the two-qubit CNOT-Dihedral group, with minimal numbers of controlled-S (CS) and controlled-X (CX) gates, using the generating set of quantum gates [X, T, CX, CS]. We…

Quantum Physics · Physics 2020-12-10 Shelly Garion , Andrew W. Cross

The current phase of quantum computing is in the Noisy Intermediate-Scale Quantum (NISQ) era. On NISQ devices, two-qubit gates such as CNOTs are much noisier than single-qubit gates, so it is essential to minimize their count. Quantum…

Quantum Physics · Physics 2022-03-24 Xin-Chuan Wu , Marc Grau Davis , Frederic T. Chong , Costin Iancu

There is no unique way to encode a quantum algorithm into a quantum circuit. With limited qubit counts, connectivities, and coherence times, circuit optimization is essential to make the best use of near-term quantum devices. We introduce…

In this Letter, we present two analytic expressions that most generally simulate $n$-qubit controlled-$U$ gates with standard one-qubit gates and CNOT gates using exponential and polynomial complexity respectively. Explicit circuits and…

Quantum Physics · Physics 2007-08-27 Yang Liu , Gui Lu Long , Yang Sun

In this work, we report on a novel quantum gate approximation algorithm based on the application of parametric two-qubit gates in the synthesis process. The utilization of these parametric two-qubit gates in the circuit design allows us to…

Quantum Physics · Physics 2022-11-16 Péter Rakyta , Zoltán Zimborás

Circuit cutting, the partitioning of quantum circuits into smaller independent fragments, has become a promising avenue for scaling up current quantum-computing experiments. Here, we introduce a scheme for joint cutting of two-qubit…

Quantum computing is a rapidly expanding field with applications ranging from optimization all the way to complex machine learning tasks. Quantum memories, while lacking in practical quantum computers, have the potential to bring quantum…

Optimizing the size and depth of CNOT circuits is an active area of research in quantum computing and is particularly relevant for circuits synthesized from the Clifford + T universal gate set. Although many techniques exist for finding…

Quantum Physics · Physics 2025-07-15 Alan Bu , Evan Fan , Robert Sanghyeon Joo

The problem of finding efficient decompositions of multi-qubit gates is of importance for quantum computing, especially, in application to existing noisy intermediate-scale quantum devices, whose resources are substantially limited. Here we…

Quantum Physics · Physics 2022-04-05 A. S. Nikolaeva , E. O. Kiktenko , A. K. Fedorov

In the noisy intermediate-scale quantum (NISQ) era, two-qubit gates in quantum circuits are more susceptible to noise than single-qubit gates. Therefore, reducing the number of two-qubit gates is crucial for improving circuit efficiency and…

Quantum Physics · Physics 2025-07-22 Kai Chen , Wen Liu , GuoSheng Xu , Yangzhi Li , Maoduo Li , Shouli He

We present an algorithm that decomposes any $n$-qubit Clifford operator into a circuit consisting of three subcircuits containing only CNOT or CPHASE gates with layers of one-qubit gates before and after each of these subcircuits. As with…

Quantum Physics · Physics 2023-10-18 Timothy Proctor , Kevin Young

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 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