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Related papers: Scalable reconstruction of density matrices

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I propose an iterative expectation maximization algorithm for reconstructing a quantum optical ensemble from a set of balanced homodyne measurements performed on an optical state. The algorithm applies directly to the acquired data,…

Quantum Physics · Physics 2009-11-10 A. I. Lvovsky

Towards the efficient simulation of near-term quantum devices using tensor network states, we introduce an improved real-space parallelizable matrix-product state (MPS) compression method. This method enables efficient compression of all…

Quantum Physics · Physics 2024-09-02 Rong-Yang Sun , Tomonori Shirakawa , Seiji Yunoki

We introduce a repeater scheme to efficiently distribute multipartite entangled states in a quantum network with optimal scaling. The scheme allows to generate graph states such as 2D and 3D cluster states of growing size or GHZ states over…

Quantum Physics · Physics 2019-01-30 Julius Wallnöfer , Alexander Pirker , Michael Zwerger , Wolfgang Dür

We present a method for quantum state tomography that enables the efficient estimation, with fixed precision, of any of the matrix elements of the density matrix of a state, provided that the states from the basis in which the matrix is…

Quantum Physics · Physics 2015-06-12 Ariel Bendersky , Juan Pablo Paz

As we enter a new era of quantum technology, it is increasingly important to develop methods to aid in the accurate preparation of quantum states for a variety of materials, matter, and devices. Computational techniques can be used to…

Designing computational experiments involving $\ell_1$ minimization with linear constraints in a finite-dimensional, real-valued space for receiving a sparse solution with a precise number $k$ of nonzero entries is, in general, difficult.…

Optimization and Control · Mathematics 2013-09-11 Christian Kruschel , Dirk A. Lorenz

Large-scale dynamic inverse problems are often ill-posed due to model complexity and the high dimensionality of the unknown parameters. Regularization is commonly employed to mitigate ill-posedness by incorporating prior information and…

Numerical Analysis · Mathematics 2026-01-21 Aryeh Keating , Mirjeta Pasha

Quantum state tomography (QST) is the gold standard technique for obtaining an estimate for the state of small quantum systems in the laboratory. Its application to systems with more than a few constituents (e.g. particles) soon becomes…

We demonstrate a novel experimental technique for quantum-state tomography of the collective density matrix. It is based on measurements of the polarization of light, traversing the atomic vapor. To assess the technique's robustness against…

Quantum Physics · Physics 2025-08-29 Marek Kopciuch , Magdalena Smolis , Adam Miranowicz , Szymon Pustelny

We develop a mathematical and numerical framework to solve state estimation problems for applications that present variations in the shape of the spatial domain. This situation arises typically in a biomedical context where inverse problems…

Numerical Analysis · Mathematics 2023-03-14 Felipe Galarce , Damiano Lombardi , Olga Mula

We present a quantum state tomography method that enables the reconstruction of \emph{arbitrary} $d-$dimensional quantum states encoded in the discretized transverse momentum of photons, by using \emph{only} $d+1$ experimental settings. To…

Quantum Physics · Physics 2025-06-23 Quimey Pears Stefano , Lorena Rebón , Claudio Iemmi

An algorithm for the simulation of the evolution of slightly entangled quantum states has been recently proposed as a tool to study time-dependent phenomena in one-dimensional quantum systems. Its key feature is a time-evolving…

Strongly Correlated Electrons · Physics 2022-08-22 A. J. Daley , C. Kollath , U. Schollwoeck , G. Vidal

We implement an algorithm which is aimed to reduce the dimensions of the Hilbert space of quantum many-body systems by means of a renormalization procedure. We test the role and importance of different representations on the reduction…

Quantum Physics · Physics 2015-05-27 Tarek Khalil , Jean Richert

For reconstructing large tomographic datasets fast, filtered backprojection-type or Fourier-based algorithms are still the method of choice, as they have been for decades. These robust and computationally efficient algorithms have been…

Numerical Analysis · Mathematics 2021-08-31 Poulami Somanya Ganguly , Daniël M. Pelt , Doga Gürsoy , Francesco de Carlo , K. Joost Batenburg

We improve upon a recently introduced efficient quantum state reconstruction procedure targeted to states well-approximated by the multi-scale entanglement renormalization ansatz (MERA), e.g., ground states of critical models. We show how…

Quantum Physics · Physics 2015-07-03 Jong Yeon Lee , Olivier Landon-Cardinal

We propose a scalable method for implementing linear optics quantum computation using the ``linked-state'' approach. Our method avoids the two-dimensional spread of errors occurring in the preparation of the linked-state. Consequently, a…

Quantum Physics · Physics 2009-11-13 Tal Mor , Nadav Yoran

Ptychography is an imaging technique in which a localized illumination scans overlapping regions of an object and generates a set of diffraction intensities used to computationally reconstruct its complex-valued transmission function. We…

Quantum Physics · Physics 2019-12-18 Mário Foganholi Fernandes , Leonardo Neves

We propose a supervised machine learning approach for boosting existing signal and image recovery methods and demonstrate its efficacy on example of image reconstruction in computed tomography. Our technique is based on a local nonlinear…

Computer Vision and Pattern Recognition · Computer Science 2013-12-02 Joseph Shtok , Michael Zibulevsky , Michael Elad

Estimation of quantum states and measurements is crucial for the implementation of quantum information protocols. The standard method for each is quantum tomography. However, quantum tomography suffers from systematic errors caused by…

Quantum Physics · Physics 2018-10-19 Adam C. Keith , Charles H. Baldwin , Scott Glancy , E. Knill

Compressed sensing is triggering a major evolution in signal acquisition. It consists in sampling a sparse signal at low rate and later using computational power for its exact reconstruction, so that only the necessary information is…

Statistical Mechanics · Physics 2012-06-07 Florent Krzakala , Marc Mézard , François Sausset , Yifan Sun , Lenka Zdeborová