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Related papers: Scalable reconstruction of density matrices

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In some cases the state of a quantum system with a large number of subsystems can be approximated efficiently by the density matrix renormalization group, which makes use of redundancies in the description of the state. Here we show that…

Strongly Correlated Electrons · Physics 2009-02-03 Michael J. Hartmann , Javier Prior , Stephen R. Clark , Martin B. Plenio

Quantum state tomography is an essential component of modern quantum technology. In application to continuous-variable harmonic-oscilator systems, such as the electromagnetic field, existing tomography methods typically reconstruct the…

Quantum Physics · Physics 2023-01-09 Ekaterina Fedotova , Nikolai Kuznetsov , Egor Tiunov , A. E. Ulanov , A. I. Lvovsky

We determine the resource scaling of machine learning-based quantum state reconstruction methods, in terms of inference and training, for systems of up to four qubits when constrained to pure states. Further, we examine system performance…

Quantum Physics · Physics 2022-01-25 Sanjaya Lohani , Thomas A. Searles , Brian T. Kirby , Ryan T. Glasser

Tomographic reconstruction of quantum states plays a fundamental role in benchmarking quantum systems and accessing information encoded in quantum-mechanical systems. Among the informationally complete sets of quantum measurements, the…

Quantum Physics · Physics 2025-06-11 Victor Gonzalez Avella , Jakub Czartowski , Dardo Goyeneche , Karol Życzkowski

We introduce an approach for performing quantum state reconstruction on systems of $n$ qubits using a machine-learning-based reconstruction system trained exclusively on $m$ qubits, where $m\geq n$. This approach removes the necessity of…

We study the possibility of performing quantum state reconstruction from a measurement record that is obtained as a sequence of expectation values of a Hermitian operator evolving under repeated application of a single random unitary map,…

Quantum Physics · Physics 2010-04-29 Seth T. Merkel , Carlos A. Riofrio , Steven T. Flammia , Ivan H. Deutsch

Quantum state tomography (QST) scales exponentially in both measurement and computational cost, making full reconstruction impractical for multi-qubit systems. Existing approaches attempt to reduce this complexity, but do not explicitly…

Quantum Physics · Physics 2026-04-24 Ayush Chambyal , Brijesh , Rakesh Sharma

Due to the exponential complexity of the resources required by quantum state tomography (QST), people are interested in approaches towards identifying quantum states which require less effort and time. In this paper, we provide a tailored…

Information Theory · Computer Science 2017-08-02 K. Li , J. Zhang , S. Cong

In this note, we describe a method for reconstructing matrix product states from a small number of efficiently-implementable measurements. Our method is exponentially faster than standard tomography, and it can also be used to certify that…

Quantum Physics · Physics 2010-02-26 Olivier Landon-Cardinal , Yi-Kai Liu , David Poulin

We present a simple and efficient Bayesian recursive algorithm for the data-pattern scheme for quantum state reconstruction, which is applicable to situations where measurement settings can be controllably varied efficiently. The algorithm…

Quantum state tomography (QST) is a fundamental task in quantum information science that aims to reconstruct unknown quantum states from measurement data. However, the exponential growth of Hilbert-space dimension with system size makes…

Quantum Physics · Physics 2026-05-27 Zhen Qin , Michael B. Wakin , Zhihui Zhu

We reconstruct a matrix product state (MPS) in reduced spaces using density matrix. This scheme applies to a MPS built on a blocked quantum lattice. Each block contains $N$ physical sites that have a local space of rank $R$. The simulation…

Strongly Correlated Electrons · Physics 2018-09-17 Lihua Wang , Kwang S. Kim

The article introduces efficient quantum state tomography schemes for qutrits and entangled qubits subject to pure decoherence. We implement the dynamic state reconstruction method for open systems sent through phase-damping channels which…

Quantum Physics · Physics 2020-11-03 Artur Czerwinski

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

The reconstruction of the state of a multipartite quantum mechanical system represents a fundamental task in quantum information science. At its most basic, it concerns a state of a bipartite quantum system whose subsystems are subjected to…

Quantum Physics · Physics 2018-05-01 Milan Holzäpfel , Marcus Cramer , Nilanjana Datta , Martin B. Plenio

The knowledge of the density matrix of a quantum state plays a fundamental role in several fields ranging from quantum information processing to experiments on foundations of quantum mechanics and quantum optics. Recently, a method has been…

Quantum Physics · Physics 2010-12-07 G. Brida , M. Genovese , M. Gramegna , A. Meda , F. Piacentini , P. Traina , E. Predazzi , S. Olivares , M. G. A. Paris

Quantum state tomography, the ability to deduce the state of a quantum system from measured data, is the gold standard for verification and benchmarking of quantum devices. It has been realized in systems with few components, but for larger…

Motivated by the Kronecker product approximation technique, we have developed a very simple method to assess the inseparability of bipartite quantum systems, which is based on a realigned matrix constructed from the density matrix. For any…

Quantum Physics · Physics 2007-05-23 Kai Chen , Ling-An Wu

Recently, tremendous progress has been made in the field of quantum science and technologies: different platforms for quantum simulation as well as quantum computing, ranging from superconducting qubits to neutral atoms, are starting to…

Impressive progress has been made in the past decade in the study of technological applications of varied types of quantum systems. With industry giants like IBM laying down their roadmap for scalable quantum devices with more than…

Quantum Physics · Physics 2021-09-15 Rishabh Gupta , Sabre Kais , Raphael D. Levine