English
Related papers

Related papers: Correlated Purification for Restoring $N$-Represen…

200 papers

Extracting tomographic information about quantum states is a crucial task in the quest towards devising high-precision quantum devices. Current schemes typically require measurement devices for tomography that are a priori calibrated to…

Quantum Physics · Physics 2023-07-13 Ingo Roth , Jadwiga Wilkens , Dominik Hangleiter , Jens Eisert

Benchmarking the performance of quantum error correction codes in physical systems is crucial for achieving fault-tolerant quantum computing. Current methodologies, such as (shadow) tomography or direct fidelity estimation, fall short in…

Quantum Physics · Physics 2024-10-17 Junjie Chen , Pei Zeng , Qi Zhao , Xiongfeng Ma , You Zhou

Scientific imaging often involves long acquisition times to obtain high-quality data, especially when probing complex, heterogeneous systems. However, reducing acquisition time to increase throughput inevitably introduces significant noise…

Artificial Intelligence · Computer Science 2025-05-14 Petrus H. Zwart , Tamas Varga , Odeta Qafoku , James A. Sethian

An implicit purification scheme is proposed for calculation of the temperature-dependent, grand canonical single-particle density matrix, given as a Fermi operator expansion in terms of the Hamiltonian. The computational complexity is shown…

Materials Science · Physics 2009-11-10 Anders M. N. Niklasson

Nuclear magnetic resonance (NMR) spectroscopy serves as an important tool to analyze chemicals and proteins in bioengineering. However, NMR signals are easily contaminated by noise during the data acquisition, which can affect subsequent…

Signal Processing · Electrical Eng. & Systems 2023-10-24 Di Guo , Runmin Xu , Jinyu Wu , Meijin Lin , Xiaofeng Du , Xiaobo Qu

Quantum state tomography is a daunting challenge of experimental quantum computing even in moderate system size. One way to boost the efficiency of state tomography is via local measurements on reduced density matrices, but the…

Quantum Physics · Physics 2019-12-03 Tao Xin , Sirui Lu , Ningping Cao , Galit Anikeeva , Dawei Lu , Jun Li , Guilu Long , Bei Zeng

Near-term quantum computers provide a promising platform for finding ground states of quantum systems, which is an essential task in physics, chemistry, and materials science. Near-term approaches, however, are constrained by the effects of…

We present a quantum impurity solver based on a pseudo-particle framework, which combines diagrammatic resummations for a three-point vertex with diagrammatic Monte Carlo sampling of a four-point vertex. This recently proposed approach [A.…

Strongly Correlated Electrons · Physics 2022-09-07 Aaram J. Kim , Jiajun Li , Martin Eckstein , Philipp Werner

Quantum process tomography (QPT) is crucial for advancing quantum technologies, including quantum computers, quantum networks and quantum sensors. Shadow process tomography (SPT) utilizes the Choi isomorphism to map QPT to shadow state…

Quantum Physics · Physics 2025-07-16 Haigang Wang , Kan He

Quantum error mitigation techniques can reduce noise on current quantum hardware without the need for fault-tolerant quantum error correction. For instance, the quasiprobability method simulates a noise-free quantum computer using a noisy…

Quantum Physics · Physics 2022-02-01 Christophe Piveteau , David Sutter , Stefan Woerner

A novel general formalism for the maximal symetrization and reduction of fields (MSRF) is proposed and applied to wavefunctions in solid state nanostructures. Its primary target is to provide an essential tool for the study and analysis of…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 S. Dalessi , M. -A. Dupertuis

Accurately describing strong electron correlation in complex systems remains a prominent challenge in computational chemistry as near-term quantum algorithms treating total correlation often require prohibitively deep circuits. Here we…

Computational Engineering, Finance, and Science · Computer Science 2026-04-21 Zhanou Liu , Yuhao Chen , Yingjin Ma , Xiao He , Yuxin Deng

Owing to the computational complexity of electronic structure algorithms running on classical digital computers, the range of molecular systems amenable to simulation remains tightly circumscribed even after many decades of work. Quantum…

Quantum Physics · Physics 2022-05-18 Alexis Ralli , Michael I. Williams , Peter V. Coveney

We present a supervised machine learning-based method using convolutional neural networks to estimate the covariance matrix of Gaussian quantum states in the presence of thermal noise. Unlike computationally intensive density matrix…

Atomic norm minimization is a convex optimization framework to recover point sources from a subset of their low-pass observations, or equivalently the underlying frequencies of a spectrally-sparse signal. When the amplitudes of the sources…

Information Theory · Computer Science 2021-02-24 Maxime Ferreira Da Costa , Yuejie Chi

Quantum processes, including quantum gates and channels, are integral to various quantum information tasks, making the efficient characterization of these processes and their underlying noise critically important. Here, we propose a…

Quantum Physics · Physics 2026-02-06 Mengru Ma , Jiangwei Shang

Quantum state tomography, which aims to find the best description of a quantum state -- the density matrix, is an essential building block in quantum computation and communication. Standard techniques for state tomography are incapable of…

Quantum Physics · Physics 2022-11-18 Markus Rambach , Akram Youssry , Marco Tomamichel , Jacquiline Romero

Quantum state tomography is a central technique for the characterization and verification of quantum systems. Standard tomography is widely used for low-dimensional systems, but for larger systems, it becomes impractical due to the…

To obtain a complete description of a quantum system, one usually employs standard quantum state tomography, which however requires exponential number of measurements to perform and hence is impractical when the system's size grows large.…

Quantum Physics · Physics 2020-01-17 Tao Xin , Xinfang Nie , Xiangyu Kong , Jingwei Wen , Dawei Lu , Jun Li

Quantum networks, which integrate multiple quantum computers and the channels connecting them, are crucial for distributed quantum information processing but remain inherently susceptible to channel noise. Channel purification emerges as a…