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Related papers: Simulating Noisy Variational Quantum Algorithms: A…

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One of the most promising applications of noisy intermediate-scale quantum computers is the simulation of molecular Hamiltonians using the variational quantum eigensolver. We show that encoding symmetries of the simulated Hamiltonian in the…

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 a classical algorithm based on sparse Pauli dynamics can efficiently simulate quantum circuits studied in a recent experiment on 127 qubits of IBM's Eagle processor [Nature 618, 500 (2023)]. Our classical simulations on a…

Quantum Physics · Physics 2023-06-29 Tomislav Begušić , Garnet Kin-Lic Chan

In the current NISQ (Noisy Intermediate-Scale Quantum) era, simulating and verifying noisy quantum circuits is crucial but faces challenges such as quantum state explosion and complex noise representations, constraining simulation and…

Quantum Physics · Physics 2025-12-12 Mingyu Huang , Ji Guan , Wang Fang , Mingsheng Ying

Approximation based on perturbation theory is the foundation for most of the quantitative predictions of quantum mechanics, whether in quantum many-body physics, chemistry, quantum field theory or other domains. Quantum computing provides…

Quantum Physics · Physics 2022-09-29 Jinzhao Sun , Suguru Endo , Huiping Lin , Patrick Hayden , Vlatko Vedral , Xiao Yuan

We propose a simple scheme to reduce readout errors in experiments on quantum systems with finite number of measurement outcomes. Our method relies on performing classical post-processing which is preceded by Quantum Detector Tomography,…

Quantum Physics · Physics 2020-04-28 Filip B. Maciejewski , Zoltán Zimborás , Michał Oszmaniec

Access to quantum computing is steadily increasing each year as the speed advantage of quantum computers solidifies with the growing number of usable qubits. However, the inherent noise encountered when running these systems can lead to…

Quantum Physics · Physics 2024-09-24 Jon Gardeazabal-Gutierrez , Erik B. Terres-Escudero , Pablo García Bringas

Quantum circuit simulators running on classical computers offer a vital platform for designing, testing, and optimizing quantum algorithms, driving innovation despite limited access to real quantum hardware. However, their scalability is…

Quantum Physics · Physics 2025-10-29 Gleb Kalachev , Pavel Mosharev , Zuoheng Zou , Pavel Panteleev , Man-Hong Yung

In the literature, the study of electron transport in quantum devices is mainly devoted to DC properties. The fluctuations of the electrical current around these DC values, the so-called quantum noise, are much less analyzed. The…

Quantum Physics · Physics 2015-03-11 Damiano Marian , Enrique Colomés , Zhen Zhan , Xavier Oriols

Quantum computation, a completely different paradigm of computing, benefits from theoretically proven speed-ups for certain problems and opens up the possibility of exactly studying the properties of quantum systems. Yet, because of the…

We analyze the robustness of Grover's quantum search algorithm performed by a quantum register under a possibly time-correlated noise acting locally on the qubits. We model the noise as originating from an arbitrary but fixed unitary…

Quantum Physics · Physics 2023-02-24 Sheikh Parvez Mandal , Ahana Ghoshal , Chirag Srivastava , Ujjwal Sen

One of the crucial steps in building a scalable quantum computer is to identify the noise sources which lead to errors in the process of quantum evolution. Different implementations come with multiple hardware-dependent sources of noise and…

Quantum Physics · Physics 2021-06-02 Daniel Stilck França , Sergii Strelchuk , Michał Studziński

Combinatorial optimization on near-term quantum devices is a promising path to demonstrating quantum advantage. However, the capabilities of these devices are constrained by high noise or error rates. In this paper, we propose an iterative…

Quantum Physics · Physics 2022-05-12 Xiaoyuan Liu , Anthony Angone , Ruslan Shaydulin , Ilya Safro , Yuri Alexeev , Lukasz Cincio

The impressive progress in quantum hardware in the last years has raised the interest of the quantum computing community in harvesting the computational power of such devices. However, in the absence of error correction, these devices can…

Quantum Physics · Physics 2023-02-21 Giacomo De Palma , Milad Marvian , Cambyse Rouzé , Daniel Stilck França

The present era of quantum processors with hundreds to thousands of noisy qubits has sparked interest in understanding the computational power of these devices and how to leverage it to solve practically relevant problems. For applications…

Quantum Physics · Physics 2026-04-15 Victor Martinez , Omar Fawzi , Daniel Stilck França

Noise is often regarded as anathema to quantum computation, but in some settings it can be an unlikely ally. We consider the problem of learning the class of $n$-bit parity functions by making queries to a quantum example oracle. In the…

Quantum Physics · Physics 2015-08-05 Andrew W. Cross , Graeme Smith , John A. Smolin

Dissipative collective effects are ubiquitous in quantum physics, and their relevance ranges from the study of entanglement in biological systems to noise mitigation in quantum computers. Here, we put forward the first fully quantum…

Variational hybrid quantum-classical algorithms (VHQCAs) are near-term algorithms that leverage classical optimization to minimize a cost function, which is efficiently evaluated on a quantum computer. Recently VHQCAs have been proposed for…

Quantum Physics · Physics 2020-04-07 Kunal Sharma , Sumeet Khatri , M. Cerezo , Patrick J. Coles

Variational Quantum Eigensolvers (VQE) are a promising approach for finding the classically intractable ground state of a Hamiltonian. The Unitary Block Optimization Scheme (UBOS) is a state-of-the-art VQE method which works by sweeping…

Quantum Physics · Physics 2024-11-04 Xiaochuan Ding , Bryan K. Clark

We define and study the complexity of robust polynomials for Boolean functions and the related fault-tolerant quantum decision trees, where input bits are perturbed by noise. We compare several different possible definitions. Our main…

Quantum Physics · Physics 2007-05-23 Harry Buhrman , Ilan Newman , Hein Roehrig , Ronald de Wolf