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Related papers: Depth optimization of CNOT ladder circuits

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Dynamic simulation of materials is a promising application for near-term quantum computers. Current algorithms for Hamiltonian simulation, however, produce circuits that grow in depth with increasing simulation time, limiting feasible…

Quantum Physics · Physics 2022-03-10 Lindsay Bassman , Roel Van Beeumen , Ed Younis , Ethan Smith , Costin Iancu , Wibe A. de Jong

We seek to develop better upper bound guarantees on the depth of quantum CZ gate, CNOT gate, and Clifford circuits than those reported previously. We focus on the number of qubits $n\,{\leq}\,$1,345,000 [1], which represents the most…

Quantum Physics · Physics 2022-08-26 Dmitri Maslov , Ben Zindorf

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

Current experimental quantum computing devices are limited by noise, mainly originating from entangling gates. If an efficient gate sequence for an operation is unknown, one often employs layered parameterized quantum circuits, especially…

Quantum Physics · Physics 2025-11-12 Tom R. Rieckmann , Stefan Scheel , A. Douglas K. Plato

We study the problem of CNOT-optimal quantum circuit synthesis over gate sets consisting of CNOT and Z-basis rotations of arbitrary angles. We show that the circuit-polynomial correspondence relates such circuits to Fourier expansions of…

Quantum Physics · Physics 2019-03-29 Matthew Amy , Parsiad Azimzadeh , Michele Mosca

The execution of quantum circuits on real systems has largely been limited to those which are simply time-ordered sequences of unitary operations followed by a projective measurement. As hardware platforms for quantum computing continue to…

Recently, deep neural networks have proven capable of predicting some output properties of relevant random quantum circuits, indicating a strategy to emulate quantum computers alternative to direct simulation methods such as, e.g.,…

Disordered Systems and Neural Networks · Physics 2025-07-24 Simone Cantori , Sebastiano Pilati

Quantum squaring operation is a useful building block in implementing quantum algorithms such as linear regression, regularized least squares algorithm, order-finding algorithm, quantum search algorithm, Newton Raphson division, Euclidean…

Quantum Physics · Physics 2024-06-05 Afrin Sultana , Edgard Muñoz-Coreas

We apply a hybrid evolutionary algorithm to minimize the depth of circuits in quantum computing. More specifically, we evaluate two different variants of the algorithm. In the first approach, we combine the evolutionary algorithm with an…

Quantum hashing is a useful technique that allows us to construct memory-efficient algorithms and secure quantum protocols. First, we present a circuit that implements the phase form of quantum hashing using $2^{n-1}$ CNOT gates, where n is…

Quantum Physics · Physics 2025-07-10 Ilnar Zinnatullin , Kamil Khadiev

A Hadamard-free Clifford transformation is a circuit composed of quantum Phase (P), CZ, and CNOT gates. It is known that such a circuit can be written as a three-stage computation, -P-CZ-CNOT-, where each stage consists only of gates of the…

Quantum Physics · Physics 2023-10-18 Dmitri Maslov , Willers Yang

Quantum simulation is a promising way toward practical quantum advantage, but noise in current quantum hardware poses a significant obstacle. We prove that not only the physical error but also the algorithmic error in a single Trotter step…

Quantum Physics · Physics 2025-10-29 Jue Xu , Chu Zhao , Junyu Fan , Qi Zhao

Quantum simulation traditionally relies on unitary dynamics, inherently imposing efficiency constraints on the generation of intricate entangled states. In principle, these limitations can be superseded by non-unitary, dynamic circuits.…

The quantum approximate optimization algorithm (QAOA) is an appealing proposal to solve NP problems on noisy intermediate-scale quantum (NISQ) hardware. Making NISQ implementations of the QAOA resilient to noise requires short ansatz…

A scalable and programmable quantum computer holds the potential to solve computationally intensive tasks that classical computers cannot accomplish within a reasonable time frame, achieving quantum advantage. However, the vulnerability of…

Quantum Physics · Physics 2025-03-04 Younghun Kim , Martin Sevior , Muhammad Usman

Compiling quantum circuits to account for hardware restrictions is an essential part of the quantum computing stack. Circuit compilation allows us to adapt algorithm descriptions into a sequence of operations supported by real quantum…

Quantum Physics · Physics 2025-10-14 Alejandro Villoria , Henning Basold , Alfons Laarman

During the noisy intermediate-scale quantum (NISQ) era, it is important to optimize the quantum circuits in circuit depth and gate count, especially entanglement gates, including the CNOT gate. Among all the unitary operators, diagonal…

Quantum Physics · Physics 2024-04-15 Xinchi Huang , Taichi Kosugi , Hirofumi Nishi , Yu-ichiro Matsushita

We introduce an improved CNOT synthesis algorithm that considers nearest-neighbour interactions and CNOT gate error rates in noisy intermediate-scale quantum (NISQ) hardware. Compared to IBM's Qiskit compiler, it improves the fidelity of a…

Quantum Physics · Physics 2024-05-31 Dohun Kim , Minyoung Kim , Sarah Meng Li , Michele Mosca

We study in detail the algebraic structures underlying quantum circuits generated by CNOT gates. Our results allow us to propose polynomial-time heuristics to reduce the number of gates used in a given CNOT circuit and we also give…

Quantum Physics · Physics 2020-12-18 Marc Bataille

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