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Related papers: Limitations of Noisy Geometrically Local Quantum C…

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We study the effect of noise on the classical simulatability of quantum circuits defined by computationally tractable (CT) states and efficiently computable sparse (ECS) operations. Examples of such circuits, which we call CT-ECS circuits,…

Quantum Physics · Physics 2020-08-28 Yasuhiro Takahashi , Yuki Takeuchi , Seiichiro Tani

Due to the unreliability and limited capacity of existing quantum computer prototypes, quantum circuit simulation continues to be a vital tool for validating next generation quantum computers and for studying variational quantum algorithms,…

Quantum Physics · Physics 2021-04-01 Yipeng Huang , Steven Holtzen , Todd Millstein , Guy Van den Broeck , Margaret Martonosi

Noise is one of the main obstacles to realizing quantum devices that achieve a quantum computational advantage. A possible approach to minimize the noise effect is to employ shallow-depth quantum circuits since noise typically accumulates…

Quantum Physics · Physics 2025-07-31 Changhun Oh

Shallow quantum circuits are believed to be the most promising candidates for achieving early practical quantum advantage - this has motivated the development of a broad range of error mitigation techniques whose performance generally…

Quantum Physics · Physics 2024-02-13 Jonathan Foldager , Bálint Koczor

Recent work by Bravyi et al. constructs a relation problem that a noisy constant-depth quantum circuit (QNC$^0$) can solve with near certainty (probability $1 - o(1)$), but that any bounded fan-in constant-depth classical circuit (NC$^0$)…

Quantum Physics · Physics 2021-09-29 Daniel Grier , Nathan Ju , Luke Schaeffer

We show that quantum circuits cannot be made fault-tolerant against a depolarizing noise level of approximately 45%, thereby improving on a previous bound of 50% (due to Razborov). Our precise quantum circuit model enables perfect gates…

Quantum Physics · Physics 2007-05-23 Harry Buhrman , Richard Cleve , Monique Laurent , Noah Linden , Alexander Schrijver , Falk Unger

We provide and experimentally demonstrate an accreditation protocol that upper-bounds the variation distance between noisy and noiseless probability distributions of the outputs of arbitrary quantum computations. We accredit the outputs of…

Quantum Physics · Physics 2021-10-13 Samuele Ferracin , Seth T. Merkel , David McKay , Animesh Datta

Realistic multi-qubit noise processes often result in error mechanisms that are not captured by the probabilistic, Markovian error models commonly employed in circuit-level analyses of quantum fault-tolerance. By working within an…

Noise is the defining feature of the NISQ era, but it remains unclear if noisy quantum devices are capable of quantum speedups. Quantum supremacy experiments have been a major step forward, but gaps remain between the theory behind these…

Quantum Physics · Physics 2022-03-08 Adam Bouland , Bill Fefferman , Zeph Landau , Yunchao Liu

Sampling from the output distributions of quantum computations comprising only commuting gates, known as instantaneous quantum polynomial (IQP) computations, is believed to be intractable for classical computers, and hence this task has…

Quantum Physics · Physics 2025-03-07 Joel Rajakumar , James D. Watson , Yi-Kai Liu

Although the emergence of a fully-functional quantum computer may still be far away from today, in the near future, it is possible to have medium-size, special-purpose, quantum devices that can perform computational tasks not efficiently…

Quantum Physics · Physics 2017-06-28 Man-Hong Yung , Xun Gao

We provide an $\Omega(log(n))$ lower bound for the depth of any quantum circuit generating the unique groundstate of Kitaev's spherical code. No circuit-depth lower bound was known before on this code in the general case where the gates can…

Quantum Physics · Physics 2018-10-10 Dorit Aharonov , Yonathan Touati

Demonstrating quantum supremacy, a complexity-guaranteed quantum advantage against over the best classical algorithms by using less universal quantum devices, is an important near-term milestone for quantum information processing. Here we…

Quantum Physics · Physics 2016-10-13 Keisuke Fujii

Understanding fault-tolerant properties of quantum circuits is important for the design of large-scale quantum information processors. In particular, simulating properties of encoded circuits is a crucial tool for investigating the…

Quantum Physics · Physics 2014-11-19 Easwar Magesan , Daniel Puzzuoli , Christopher E. Granade , David G. Cory

Recent work [M. J. Gullans et al., Physical Review X, 11(3):031066 (2021)] has shown that quantum error correcting codes defined by random Clifford encoding circuits can achieve a non-zero encoding rate in correcting errors even if the…

Quantum Physics · Physics 2024-07-18 Andrew S. Darmawan , Yoshifumi Nakata , Shiro Tamiya , Hayata Yamasaki

Simulating open quantum systems on quantum computers presents a fundamental challenge: open quantum dynamics are intrinsically nonunitary, whereas quantum computers operate through unitary evolution. Conventional approaches overcome this…

Quantum Physics · Physics 2025-10-27 Sameer Dambal , Akira Sone , Yu Zhang

Variational Quantum Algorithms (VQAs) have been extensively researched for applications in Quantum Machine Learning (QML), Optimization, and Molecular simulations. Although designed for Noisy Intermediate-Scale Quantum (NISQ) devices, VQAs…

Quantum Physics · Physics 2026-03-24 Aakash Ravindra Shinde , Arianne Meijer - van de Griend , Jukka K. Nurminen

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 errors in noisy environments remain a major obstacle to advancing quantum information technology. In this work, we expand a recently developed geometric framework, originally utilized for analyzing noise accumulation and creating…

Quantum Physics · Physics 2024-07-11 Junkai Zeng , Yong-Ju Hai , Hao Liang , Xiu-Hao Deng

We investigate the amount of noise required to turn a universal quantum gate set into one that can be efficiently modelled classically. This question is useful for providing upper bounds on fault tolerant thresholds, and for understanding…

Quantum Physics · Physics 2007-05-23 S. Virmani , Susana F. Huelga , Martin B. Plenio