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Related papers: Permutationally invariant state reconstruction

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In continuous-variable tomography, with finite data and limited computation resources, reconstruction of a quantum state of light is performed on a finite-dimensional subspace. No systematic method was ever developed to assign such a…

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 revisit quantum tomography in an informationally incomplete scenario and propose improved state reconstruction methods using deep neural networks. In the first approach, the trained network predicts an optimal linear or quadratic…

Quantum Physics · Physics 2026-01-21 Mateusz Krawczyk , Pavel Baláž , Katarzyna Roszak , Jarosław Pawłowski

An iterative algorithm for the reconstruction of an unknown quantum state from the results of incompatible measurements is proposed. It consists of Expectation-Maximization step followed by a unitary transformation of the eigenbasis of the…

Quantum Physics · Physics 2009-11-06 J. Rehacek , Z. Hradil , M. Jezek

Quantum state tomography is an integral part of quantum computation and offers the starting point for the validation of various quantum devices. One of the central tasks in the field of state tomography is to reconstruct with high fidelity,…

Quantum Physics · Physics 2022-12-21 Rishabh Gupta , Manas Sajjan , Raphael D. Levine , Sabre Kais

Quantum state tomography is a key technique for quantum information processing, but is challenging due to the exponential growth of its complexity with the system size. In this work, we propose an algorithm which iteratively finds the best…

Quantum Physics · Physics 2022-05-13 Donghong Han , Chu Guo , Xiaoting Wang

We introduce a variational quantum computing approach for quantum state reconstruction within a discretized logical framework, using experimental measurement data as input. By mapping the reconstruction cost function onto an Ising model,…

Quantum Physics · Physics 2026-04-03 Mwezi Koni , Shawal Kassim , Paola C. Obando , Neelan Gounden , Isaac Nape

Due to the complexity of the space of quantum many-body states the computation of expectation values by statistical sampling is, in general, a hard task. Neural network representations of such quantum states which can be physically…

Quantum Physics · Physics 2019-12-04 Stefanie Czischek , Jan M. Pawlowski , Thomas Gasenzer , Martin Gärttner

Resource-efficient quantum state tomography is one of the key ingredients of future quantum technologies. In this work, we propose a new tomography protocol combining standard quantum state reconstruction methods with an attention-based…

Quantum state tomography is a key process in most quantum experiments. In this work, we employ quantum machine learning for state tomography. Given an unknown quantum state, it can be learned by maximizing the fidelity between the output of…

As quantum technologies advance, the ability to generate increasingly large quantum states has experienced rapid development. In this context, the verification and estimation of large entangled systems represents one of the main challenges…

Quantum Physics · Physics 2022-03-30 Joshua Morris , Valeria Saggio , Aleksandra Gočanin , Borivoje Dakić

The exact reconstruction of many-body quantum systems is one of the major challenges in modern physics, because it is impractical to overcome the exponential complexity problem brought by high-dimensional quantum many-body systems.…

Quantum Physics · Physics 2021-04-13 Huikang Huang , Haozhen Situ , Shenggen Zheng

To improve the efficiency of the state tomography strategy via weak value, we have searched the optimal coupling strength between the system and measuring device. For an arbitrary d-dimensional quantum system, the optimal strengths being…

Quantum Physics · Physics 2024-02-23 Xuanmin Zhu , Dezheng Zhang , Runping Gao , Qun wei , Lixia Liu , Zijiang Luo

Quantum state tomography (QST) is plagued by the ``curse of dimensionality'' due to the exponentially-scaled complexity in measurement and data post-processing. Efficient QST schemes for large-scale mixed states are currently missing. In…

Quantum Physics · Physics 2023-08-15 Wen-jun Li , Kai Xu , Heng Fan , Shi-ju Ran , Gang Su

The field of quantum information has been growing fast over the past decade. Optical quantum computation, based on the concepts of KLM and cluster states, has witnessed experimental realizations of larger and more complex systems in terms…

Quantum Physics · Physics 2014-11-11 Dikla Oren , Yoav Shechtman , Maor Mutzafi , Yonina C. Eldar , Mordechai Segev

We introduce a scheme to reconstruct arbitrary states of networks composed of quantum oscillators--e.g., the motional state of trapped ions or the radiation state of coupled cavities. The scheme uses minimal resources, in the sense that it…

Quantum Physics · Physics 2013-09-10 Tommaso Tufarelli , Alessandro Ferraro , M. S. Kim , Sougato Bose

System of 1/2 spin particles is observed repeatedly using Stern-Gerlach apparatuses with rotated orientations. Synthesis of such non-commuting observables is analyzed using maximum likelihood estimation as an example of quantum state…

Quantum Physics · Physics 2009-10-31 Z. Hradil , J. Summhammer , G. Badurek , H. Rauch

Quantum tomography is an essential method of the photonic technology toolbox and is routinely used for evaluation of experimentally prepared states of light and characterization of devices transforming such states. The tomography procedure…

Quantum Physics · Physics 2018-12-18 Radim Hošák , Robert Stárek , Miroslav Ježek

Quantum state tomography (QST) via local measurements on reduced density matrices (LQST) is a promising approach but becomes impractical for large systems. To tackle this challenge, we developed an efficient quantum state tomography method…

Entanglement among a large number of qubits is a crucial resource for many quantum algorithms. Such many-body states have been efficiently generated by entangling a chain of itinerant photonic qubits in the optical or microwave domain.…