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Demonstrating quantum advantage using conventional quantum algorithms remains challenging on current noisy gate-based quantum computers. Automated quantum circuit synthesis via quantum machine learning has emerged as a promising solution,…

Quantum Physics · Physics 2025-04-14 Shubing Xie , Aritra Sarkar , Sebastian Feld

We give quantum circuits that simulate an arbitrary two-qubit unitary operator up to global phase. For several quantum gate libraries we prove that gate counts are optimal in worst and average cases. Our lower and upper bounds compare…

Quantum Physics · Physics 2013-05-29 Vivek V. Shende , Igor L. Markov , Stephen S. Bullock

Qubit Mapping is a critical aspect of implementing quantum circuits on real hardware devices. Currently, the existing algorithms for qubit mapping encounter difficulties when dealing with larger circuit sizes involving hundreds of qubits.…

Typical quantum gate tomography protocols struggle with a self-consistency problem: the gate operation cannot be reconstructed without knowledge of the initial state and final measurement, but such knowledge cannot be obtained without…

The Swap gate is a ubiquitous tool for moving information on quantum hardware, yet it can be considered a classical operation because it does not entangle product states. Genuinely quantum operations could outperform Swap for the task of…

Quantum Physics · Physics 2023-02-02 Aniruddha Bapat , Andrew M. Childs , Alexey V. Gorshkov , Eddie Schoute

Near-term quantum computers often have connectivity constraints, i.e. restrictions, on which pairs of qubits in the device can interact. Optimally mapping a quantum circuit to a hardware topology under these constraints is a difficult task.…

Quantum Physics · Physics 2026-03-02 Gurleen Padda , Edwin Tham , Aharon Brodutch , Dave Touchette

Quantum circuit synthesis and compilation are critical components in the quantum computing stack, both for contemporary quantum systems, where efficient use of limited resources is essential, as well as for large-scale fault-tolerant…

Quantum Physics · Physics 2025-10-21 Jonathan Nemirovsky , Maya Chuchem , Lee Peleg , Yakov Solomons , Amit Ben Kish , Yotam Shapira

We propose a method to construct composite two-qubit gates with narrowband profiles with respect to the spin-spin coupling. The composite sequences are selective to the variations in the amplitude and duration of the spin-spin coupling, and…

Quantum Physics · Physics 2022-06-30 Boyan T. Torosov , Nikolay V. Vitanov

As quantum devices scale toward practical machine learning applications, the binary qubit paradigm faces expressivity and resource efficiency limitations. Multi-level quantum systems, or qudits, offer a promising alternative by harnessing a…

Quantum Physics · Physics 2025-05-09 Tiago de Souza Farias , Lucas Friedrich , Jonas Maziero

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

We present evidence that there exist quantum computations that can be carried out in constant depth, using 2-qubit gates, that cannot be simulated classically with high accuracy. We prove that if one can simulate these circuits classically…

Quantum Physics · Physics 2014-05-28 Barbara M. Terhal , David P. DiVincenzo

Quantum circuits must run on quantum computers with tight limits on qubit and gate counts. To generate circuits respecting both limits, a promising opportunity is exploiting uncomputation to trade qubits for gates. We present Reqomp, a…

Quantum Physics · Physics 2024-02-21 Anouk Paradis , Benjamin Bichsel , Martin Vechev

Quantum computers require precise control over parameters and careful engineering of the underlying physical system. In contrast, neural networks have evolved to tolerate imprecision and inhomogeneity. Here, using a reservoir computing…

Quantum Physics · Physics 2021-12-13 Sanjib Ghosh , Tanjung Krisnanda , Tomasz Paterek , Timothy C. H. Liew

I describe the use of techniques based on composite rotations to combat systematic errors in controlled phase gates, which form the basis of two qubit quantum logic gates. Although developed and described within the context of Nuclear…

Quantum Physics · Physics 2007-05-23 Jonathan A. Jones

Quantum machine learning offers promising advantages for classification tasks, but noise, decoherence, and connectivity constraints in current devices continue to limit the efficient execution of feature map-based circuits. Gate Assessment…

Machine Learning · Computer Science 2026-03-23 F. Rodríguez-Díaz , D. Gutiérrez-Avilés , A. Troncoso , F. Martínez-Álvarez

The quantum circuit model allows gates between any pair of qubits yet physical instantiations allow only limited interactions. We address this problem by providing an interaction graph together with an efficient method for compiling quantum…

Quantum Physics · Physics 2016-09-07 Stephen Brierley

Clifford circuit optimization is an important step in the quantum compilation pipeline. Major compilers employ heuristic approaches. While they are fast, their results are often suboptimal. Minimization of noisy gates, like 2-qubit CNOT…

Quantum Physics · Physics 2025-04-02 Irfansha Shaik , Jaco van de Pol

Quantum computers have the potential to outperform classical computers, but are currently limited in their capabilities. One such limitation is the restricted connectivity between qubits, as captured by the hardware's coupling graph. This…

Quantum Physics · Physics 2023-06-09 Joris Kattemölle , Seenivasan Hariharan

Quantum computers are expected to scale in size to close the gap that currently exists between quantum algorithms and quantum hardware. To this end, quantum compilation techniques must scale along with the hardware constraints, shifting the…

Quantum Physics · Physics 2025-01-22 Pau Escofet , Alejandro Gonzalvo , Eduard Alarcón , Carmen G. Almudéver , Sergi Abadal

Qubit-based variational quantum algorithms have undergone rapid development in recent years but still face several challenges. In this context, we propose a symmetry-enhanced digitized counterdiabatic quantum algorithm utilizing qudits…