English
Related papers

Related papers: Least-squares inversion for density-matrix reconst…

200 papers

We present a numerical method for calculating piecewise smooth spectral functions of correlated quantum systems in the thermodynamic limit from the spectra of finite systems computed using the dynamical or correction-vector density-matrix…

Strongly Correlated Electrons · Physics 2014-05-05 Martin Paech , Eric Jeckelmann

Using measure theoretic arguments, we provide a general framework for describing and studying the general linear inverse dispersion problem where no a priori assumptions on the source function has been made. We investigate the source-sensor…

Atmospheric and Oceanic Physics · Physics 2014-09-18 Niklas Brännström , Leif Å Persson

The classical iteratively reweighted least-squares (IRLS) algorithm aims to recover an unknown signal from linear measurements by performing a sequence of weighted least squares problems, where the weights are recursively updated at each…

Machine Learning · Statistics 2024-06-06 Chiraag Kaushik , Justin Romberg , Vidya Muthukumar

Learning physical properties of high-dimensional states is crucial for developing quantum technologies but usually consumes an exceedingly large number of samples which are difficult to afford in practice. In this Letter, we use the…

Quantum Physics · Physics 2024-07-29 Da-Jian Zhang , D. M. Tong

Quantum states are successfully reconstructed using the maximum likelihood estimation on the subspace where the measured projectors reproduce the identity operator. Reconstruction corresponds to normalization of incompatible observations.…

Quantum Physics · Physics 2008-11-26 Z. Hradil , J. Summhammer , H. Rauch

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

Quantum state tomography (QST) aims at reconstructing the state of a quantum system. However in conventional QST the number of measurements scales exponentially with the number of qubits. Here we propose a QST protocol, in which the…

Quantum Physics · Physics 2024-08-23 Daniele Binosi , Giovanni Garberoglio , Diego Maragnano , Maurizio Dapor , Marco Liscidini

We propose a high efficiency tomographic scheme to reconstruct an unknown quantum state of the qubits by using a series of quantum nondemolition (QND) measurements. The proposed QND measurements of the qubits are implemented by probing the…

Quantum Physics · Physics 2015-05-20 J. S. Huang , L. F. Wei , C. H. Oh

This paper is concerned with the question of reconstructing a vector in a finite-dimensional real or complex Hilbert space when only the magnitudes of the coefficients of the vector under a redundant linear map are known. We present new…

Functional Analysis · Mathematics 2012-07-06 Radu Balan

Reconstructing a quantum system's Hamiltonian from limited yet experimentally observable information is interesting both as a practical task and from a fundamental standpoint. We pose and investigate the inverse problem of reconstructing a…

Disordered Systems and Neural Networks · Physics 2025-09-12 Nisarga Paul , Andrew Ma , Kevin P. Nuckolls

Using a perturbation technique, we derive a new approximate filtering and smoothing methodology generalizing along different directions several existing approaches to robust filtering based on the score and the Hessian matrix of the…

Methodology · Statistics 2023-06-06 Giuseppe Buccheri , Giacomo Bormetti , Fulvio Corsi , Fabrizio Lillo

In this paper, a reconstruction method for the spatially distributed dielectric constant of a medium from the back scattering wave field in the frequency domain is considered. Our approach is to propose a globally convergent algorithm,…

Analysis of PDEs · Mathematics 2016-03-01 Michael V. Klibanov , Loc H. Nguyen , Anders Sullivan , Lam Nguyen

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…

The paper addresses the generalization of the half-quadratic minimization method for the restoration of images having values in a complete Riemannian manifold. We recall the half-quadratic minimization method using the notation of the…

Numerical Analysis · Mathematics 2018-12-10 Ronny Bergmann , Raymond H. Chan , Ralf Hielscher , Johannes Persch , Gabriele Steidl

Reduced density matrices (RDMs) are fundamental in quantum information processing, allowing the computation of local observables, such as energy and correlation functions, without the exponential complexity of fully characterizing quantum…

Quantum Physics · Physics 2025-06-13 Zherui Jerry Wang , David Dechant , Yash J. Patel , Jordi Tura

The article concerns compressed sensing methods in the quaternion algebra. We prove that it is possible to uniquely reconstruct - by $\ell_1$ norm minimization - a sparse quaternion signal from a limited number of its real linear…

Functional Analysis · Mathematics 2016-05-26 Agnieszka Badenska , Łukasz Błaszczyk

We address the problem of sparse recovery in an online setting, where random linear measurements of a sparse signal are revealed sequentially and the objective is to recover the underlying signal. We propose a reweighted least squares (RLS)…

Machine Learning · Computer Science 2017-06-30 Subhadip Mukherjee , Deepak R. , Huaijin Chen , Ashok Veeraraghavan , Chandra Sekhar Seelamantula

To reconstruct a mixed or pure quantum state of a spin s is possible through coherent states: its density matrix is fixed by the probabilities to measure the value s along 4s(s+1) appropriately chosen directions in space. Thus, after…

Quantum Physics · Physics 2007-05-23 Stefan Weigert

This study presents a noise-robust framework for 1-bit diffraction tomography, a novel imaging approach that relies on intensity-only binary measurements obtained through coded apertures. The proposed reconstruction scheme leverages random…

Information Theory · Computer Science 2025-05-27 Pengwen Chen , Albert Fannjiang

We present an algorithm for the calculation of eigenstates with definite linear momentum in quantum lattices. Our method is related to the Density Matrix Renormalization Group, and makes use of the distribution of multipartite entanglement…

Strongly Correlated Electrons · Physics 2009-11-11 D. Porras , F. Verstraete , J. I. Cirac