English
Related papers

Related papers: Density matrix reconstruction from displaced photo…

200 papers

In this paper, we develop a novel phase retrieval approach to reconstruct x-ray differential phase shift induced by an object. A primary advantage of our approach is a higher-order accuracy over that with the conventional linear…

Medical Physics · Physics 2010-03-18 Wenxiang Cong , Ge Wang

We present a novel technique in which the total internal quantum state of an atom may be reconstructed via the measurement of the momentum transferred to an atom following its interaction with a near resonant travelling wave laser beam. We…

Quantum Physics · Physics 2007-05-23 B. T. H. Varcoe , R. Sang , W. R. MacGillivray , M. C. Standage

We calculate the decay rate for a state prepared in a thermal density matrix centered on a metastable ground state. We find a rate that is intrinsically time {\it dependent}, as opposed to the {\it constant} rates of previous works. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Boyanovsky , R. Holman , D. -S. Lee , J. P. Silva , A. Singh

We present a Machine Learning-based method for tomographic reconstruction of dense layered objects, with range of projection angles limited to $\pm $10$^\circ$. Whereas previous approaches to phase tomography generally require two steps,…

Image and Video Processing · Electrical Eng. & Systems 2020-01-08 Alexandre Goy , Girish Rughoobur , Shuai Li , Kwabena Arthur , Akintunde I. Akinwande , George Barbastathis

Most quantum tomographic methods can only be used for one-dimensional problems. We show how to infer the quantum state of a non-relativistic N-dimensional harmonic oscillator system by simple inverse Radon transforms. The procedure is…

Quantum Physics · Physics 2009-11-11 Anders S. Mouritzen , Klaus Molmer

A review is given on phase-sensitive measurements, such as homodyne detection, for radiation fields and material systems. Methods of quantum-state reconstruction are considered for radiation fields, including multimode and pulsed radiation.…

Quantum Physics · Physics 2009-07-10 Dirk-Gunnar Welsch , Werner Vogel , Tomas Opatrny

Phase retrieval problems in antenna measurements arise when a reference phase cannot be provided to all measurement locations. Phase retrieval algorithms require sufficiently many independent measurement samples of the radiated fields to be…

Signal Processing · Electrical Eng. & Systems 2022-06-24 Josef Knapp , Alexander Paulus , Jonas Kornprobst , Uwe Siart , Thomas F. Eibert

A quantum system's state is identified with a density matrix. Though their probabilistic interpretation is rooted in ensemble theory, density matrices embody a known shortcoming. They do not completely express an ensemble's physical…

Quantum Physics · Physics 2021-06-30 Fabio Anza , James P. Crutchfield

Digital images are commonly represented as regular 2D arrays, so pixels are organized in form of a matrix addressed by integers. However, there are many image processing operations, such as rotation or motion compensation, that produce…

Computer Vision and Pattern Recognition · Computer Science 2022-05-24 Ján Koloda , Jürgen Seiler , André Kaup

We give a new, very general, formulation of the compressed sensing problem in terms of coordinate projections of an analytic variety, and derive sufficient sampling rates for signal reconstruction. Our bounds are linear in the coherence of…

Machine Learning · Computer Science 2013-11-05 Franz J. Király , Louis Theran

Here we introduce the Delaunay Density Estimator Method. Its purpose is rendering a fully volume-covering reconstruction of a density field from a set of discrete data points sampling this field. Reconstructing density or intensity fields…

Astrophysics · Physics 2007-05-23 W. E. Schaap , R. van de Weygaert

We present a novel approach for reconstructing the projected mass distribution of clusters of galaxies from sparse and noisy weak gravitational lensing shear data. The reconstructions are regularised using knowledge gained from numerical…

Astrophysics · Physics 2009-11-24 Phil Marshall

Markov random fields are used to model high dimensional distributions in a number of applied areas. Much recent interest has been devoted to the reconstruction of the dependency structure from independent samples from the Markov random…

Computational Complexity · Computer Science 2010-03-09 Guy Bresler , Elchanan Mossel , Allan Sly

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

A possible method to reconstruct the cosmic equation of state using strong gravitational lensing systems is proposed. The feasibility of the method is investigated by carrying out the reconstruction on the basis of a simple Monte-Carlo…

Astrophysics · Physics 2009-11-06 Kazuhiro Yamamoto , Toshifumi Futamase

We demonstrate a practical possibility of loss compensation in measured photocounting statistics in the presence of dark counts and background radiation noise. It is shown that satisfactory results are obtained even in the case of low…

Quantum Physics · Physics 2009-07-18 V. N. Starkov , A. A. Semenov , H. V. Gomonay

Using tomographic reconstruction we determine the complete internuclear quantum state, represented by the Wigner function, of a dissociating I2 molecule based on femtosecond time resolved position and momentum distributions of the atomic…

Quantum Physics · Physics 2009-11-10 Esben Skovsen , Henrik Stapelfeldt , Soren Juhl , Klaus Molmer

Phase retrieval consists in the recovery of a complex-valued signal from intensity-only measurements. As it pervades a broad variety of applications, many researchers have striven to develop phase-retrieval algorithms. Classical approaches…

Starting from a frequency diffusion process for a tagged photon which simulates relaxation to the Planck law, we introduce a resetting where photons lower their frequency at random times. We consider two versions, one where the resetting to…

Statistical Mechanics · Physics 2022-10-13 Guilherme Eduardo Freire Oliveira , Christian Maes , Kasper Meerts

Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, also an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction…