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Related papers: Quantum circuits for exact unitary $t$-designs and…

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Quantum circuits with local unitaries have emerged as a rich playground for the exploration of many-body quantum dynamics of discrete-time systems. While the intrinsic locality makes them particularly suited to run on current quantum…

Today's experimental noisy quantum processors can compete with and surpass all known algorithms on state-of-the-art supercomputers for the computational benchmark task of Random Circuit Sampling [1-5]. Additionally, a circuit-based quantum…

Quantum Physics · Physics 2024-01-22 K. Kechedzhi , S. V. Isakov , S. Mandrà , B. Villalonga , X. Mi , S. Boixo , V. Smelyanskiy

In this work, a quantum error correction (QEC) procedure with the concatenated five-qubit code is used to construct a near-perfect effective qubit channel (with a error below $10^{-5}$) from arbitrary noise channels. The exact performance…

Quantum Physics · Physics 2015-11-20 Long Huang , Bo You , Xiaohua Wu , Tao Zhou

Quantum computing has proven to be capable of accelerating many algorithms by performing tasks that classical computers cannot. Currently, Noisy Intermediate Scale Quantum (NISQ) machines struggle from scalability and noise issues to render…

Emerging Technologies · Computer Science 2023-09-20 Chao Lu , Navnil Choudhury , Utsav Banerjee , Abdullah Ash Saki , Kanad Basu

A new class of protocols called mirror benchmarking was recently proposed to measure the system-level performance of quantum computers. These protocols involve circuits with random sequences of gates followed by mirroring, that is,…

Instabilities due to extrinsic interference are routinely faced in systems engineering, and a common solution is to rely on a broad class of $\textit{filtering}$ techniques in order to afford stability to intrinsically unstable systems. For…

Quantum Physics · Physics 2015-06-19 A. Soare , H. Ball , D. Hayes , J. Sastrawan , M. C. Jarratt , J. J. McLoughlin , X. Zhen , T. J. Green , M. J. Biercuk

Designing high-precision and efficient schemes is of crucial importance for quantum parameter estimation in practice. The estimation scheme based on continuous quantum measurement is one possible type of this, which looks also the most…

Quantum Physics · Physics 2019-03-12 Cheng Zhang , Kai Zhou , Wei Feng , Xin-Qi Li

We present a framework that utilizes quantum algorithms, an architecture aware quantum noise model and an ideal simulator to benchmark quantum computers. The benchmark metrics highlight the difference between the quantum computer evolution…

Quantum Physics · Physics 2021-12-20 Konstantinos Georgopoulos , Clive Emary , Paolo Zuliani

Cloud-based quantum computing, coupled with the rapid progress in quantum algorithms, brings to the forefront the question of verifiability in delegated quantum computations. In the current landscape of noisy quantum devices, this question…

Quantum Physics · Physics 2025-12-01 Anne Broadbent , Joshua Nevin

Quantum computing has been moving from a theoretical phase to practical one, presenting daunting challenges in implementing physical qubits, which are subjected to noises from the surrounding environment. These quantum noises are ubiquitous…

Current development in programmable analogue quantum simulators (AQS), whose physical implementation can be realised in the near-term compared to those of large-scale digital quantum computers, highlights the need for robust testing…

Quantum Physics · Physics 2020-08-10 Ellen Derbyshire , Jorge Yago Malo , Andrew Daley , Elham Kashefi , Petros Wallden

In this work, we study distributions of unitaries generated by random quantum circuits containing only symmetry-respecting gates. We develop a unified approach applicable to all symmetry groups and obtain an equation that determines the…

Quantum Physics · Physics 2024-10-16 Hanqing Liu , Austin Hulse , Iman Marvian

We use a random search technique to find quantum gate sequences that implement perfect quantum state preparation or unitary operator synthesis with arbitrary targets. This approach is based on the recent discovery that there is a large…

Quantum Physics · Physics 2024-10-25 Sahel Ashhab , Fumiki Yoshihara , Miwako Tsuji , Mitsuhisa Sato , Kouichi Semba

Quantum processors are now able to run quantum circuits that are infeasible to simulate classically, creating a need for benchmarks that assess a quantum processor's rate of errors when running these circuits. Here, we introduce a general…

Quantum Physics · Physics 2025-10-29 Jordan Hines , Timothy Proctor

Designing quantum processors is a complex task that demands advanced verification methods to ensure their correct functionality. However, traditional methods of comprehensively verifying quantum devices, such as quantum process tomography,…

Quantum Physics · Physics 2025-08-04 Keren Li , Peng Yan , Hanru Jiang , Nengkun Yu

Near-term quantum computers have been built as intermediate-scale quantum devices and are fragile against quantum noise effects, namely, NISQ devices. Traditional quantum-error-correcting codes are not implemented on such devices and to…

Quantum Physics · Physics 2024-03-18 Yusuke Hama , Hirofumi Nishi

We develop and demonstrate a technique to engineer universal unitary baths in quantum systems. Using the correspondence between unitary decoherence due to ambient environmental noise and errors in a control system for quantum bits, we show…

Quantum Physics · Physics 2015-06-19 A. Soare , H. Ball , D. Hayes , X. Zhen , M. C. Jarratt , J. Sastrawan , H. Uys , M. J. Biercuk

Understanding how noise influences nonequilibrium quantum critical dynamics is essential for both fundamental physics and the development of practical quantum technologies. While the quantum Kibble-Zurek (QKZ) mechanism predicts universal…

Quantum Physics · Physics 2026-03-31 Brendan Rhyno , Swarnadeep Majumder , Smitha Vishveshwara , Khadijeh Najafi

We construct $\varepsilon$-approximate unitary $k$-designs on $n$ qubits in circuit depth $O(\log k \log \log n k / \varepsilon)$. The depth is exponentially improved over all known results in all three parameters $n$, $k$, $\varepsilon$.…

Quantum Physics · Physics 2025-07-22 Laura Cui , Thomas Schuster , Fernando Brandao , Hsin-Yuan Huang

Until very recently, it was generally believed that the (approximate) 2-design property is strictly stronger than anti-concentration of random quantum circuits, mainly because it was shown that the latter anti-concentrate in logarithmic…

Quantum Physics · Physics 2025-12-09 Markus Heinrich , Jonas Haferkamp , Ingo Roth , Jonas Helsen