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We have studied theoretical un-symmetric multi-photon subtracted twin beam state and demonstrated a method for generating states that resembles to high photon number states with the increase in the number of subtracted photons through…

Quantum Physics · Physics 2021-10-05 N. Samantaray , J. C. F. Matthews , J. G. Rarity

The principle of maximum likelihood reconstruction has proven to yield satisfactory results in the context of quantum state tomography for many-body systems of moderate system sizes. Until recently, however, quantum state tomography has…

Quantum Physics · Physics 2014-01-29 Tillmann Baumgratz , Alexander Nüßeler , Marcus Cramer , Martin B. Plenio

We give a detailed account of an efficient search algorithm for the data pattern tomography proposed by J. Rehacek, D. Mogilevtsev, and Z. Hradil [Phys. Rev. Lett.~\textbf{105}, 010402 (2010)], where the quantum state of a system is…

In this work, we consider the problem of online (real-time, single-shot) estimation of static or slow-varying parameters along quantum trajectories in quantum dynamical systems. Based on the measurement signal of a continuously-monitored…

Quantum Physics · Physics 2024-06-19 Henrik Glavind Clausen , Pierre Rouchon , Rafal Wisniewski

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

A new algorithmic framework is presented for holographic phase retrieval via maximum likelihood optimization, which allows for practical and robust image reconstruction. This framework is especially well-suited for holographic coherent…

Image and Video Processing · Electrical Eng. & Systems 2022-02-18 David A. Barmherzig , Ju Sun

Maximum likelihood iteration is one of the most commonly used reconstruction algorithms in quantum tomography. The main appeal of the method is that it is easy to implement and that it converges reliably to a physically meaningful density…

Quantum Physics · Physics 2025-08-21 Florian Oberender

In the framework of noisy quantum homodyne tomography with efficiency parameter $0 < \eta \leq 1$, we propose two estimators of a quantum state whose density matrix elements $\rho_{m,n}$ decrease like $e^{-B(m+n)^{r/ 2}}$, for fixed known…

Statistics Theory · Mathematics 2009-11-13 Jean-Marie Aubry , Cristina Butucea , Katia Méziani

In this work, we propose a machine learning-based approach to address a specific aspect of the Quantum Marginal Problem: reconstructing a global density matrix compatible with a given set of quantum marginals. Our method integrates a…

Quantum Physics · Physics 2025-10-03 Daniel Uzcategui-Contreras , Antonio Guerra , Sebastian Niklitschek , Aldo Delgado

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

We propose a coherent method for the detection and reconstruction of gravitational wave signals for a network of interferometric detectors. The method is derived using the likelihood functional for unknown signal waveforms. In the standard…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Klimenko , S. Mohanty , M. Rakhmanov , G. Mitselmakher , .

The density matrix of a nonrelativistic wave-packet in an arbitrary, one-dimensional and time-dependent potential can be reconstructed by measuring hydrodynamical moments of the Wigner distribution. An n-th order Taylor polynomial in the…

Quantum Physics · Physics 2011-08-04 Lars M. Johansen

A single-photon Fock state has been generated by means of conditional preparation from a two-photon state emitted in the process of spontaneous parametric down-conversion. A recently developed high-frequency homodyne tomography technique…

Quantum Physics · Physics 2007-05-23 Alessandro Zavatta , Silvia Viciani , Marco Bellini

We propose a systematic procedure to optimize quantum state tomography protocols for continuous variable systems based on excitation counting preceded by a displacement operation. Compared with conventional tomography based on Husimi or…

Ultrafast continuous-variable quantum states offer new opportunities for advanced quantum technologies, but efficient homodyne detection of these states remains challenging. Here, we present a method for efficient ultrafast homodyne…

Quantum Physics · Physics 2026-05-15 Young-Do Yoon , Chan Roh , Geunhee Gwak , Young-Sik Ra

It is shown how it is possible to reconstruct the initial state of a one-dimensional system by measuring sequentially two conjugate variables. The procedure relies on the quasi-characteristic function, the Fourier-transform of the Wigner…

Quantum Physics · Physics 2013-01-07 Antonio Di Lorenzo

We present a universal technique for quantum state estimation based on the maximum-likelihood method. This approach provides a positive definite estimate for the density matrix from a sequence of measurements performed on identically…

Quantum Physics · Physics 2009-10-31 K. Banaszek , G. M. D'Ariano , M. G. A. Paris , M. F. Sacchi

We present a filtered backprojection algorithm for reconstructing the Wigner function of a system of large angular momentum j from Stern-Gerlach-type measurements. Our method is advantageous over the full determination of the density matrix…

Quantum Physics · Physics 2015-03-17 Roman Schmied , Philipp Treutlein

We study the efficiency of quantum algorithms which aim at obtaining phase space distribution functions of quantum systems. Wigner and Husimi functions are considered. Different quantum algorithms are envisioned to build these functions,…

Quantum Physics · Physics 2007-05-23 M. Terraneo , B. Georgeot , D. L. Shepelyansky

We describe a novel tool for the quantum characterization of optical devices. The experimental setup involves a stable reference state that undergoes an unknown quantum transformation and is then revealed by balanced homodyne detection.…