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Related papers: An Improved Quantum Projection Filter

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In this article, we study the continuous-discrete projection filter for exponential-family manifolds with conjugate likelihoods. We first derive the local projection error of the prediction step of the continuous-discrete projection filter.…

Optimization and Control · Mathematics 2026-02-11 Muhammad F. Emzir , Zaid A. Sawlan , Sami El Ferik

These notes are intended as an introduction to noncommutative (quantum) filtering theory. An introduction to quantum probability theory is given, focusing on the spectral theorem and the conditional expectation as the least squares…

Mathematical Physics · Physics 2007-05-23 Luc Bouten , Ramon van Handel

In this work, we adopt the Gradient Projection Method (GPM) to problems of quantum control. For general $N$-level closed and open quantum systems, we derive the corresponding adjoint systems and gradients of the objective functionals, and…

Quantum Physics · Physics 2025-09-03 Oleg Morzhin , Alexander Pechen

Common filters are usually based on the linear approximation of the optimal minimum mean square error estimator. The Extended and Unscented Kalman Filters handle nonlinearity through linearization and unscented transformation, respectively,…

Information Theory · Computer Science 2025-06-09 Simone Servadio , Chiran Cherian

A key challenge when designing particle filters in high-dimensional state spaces is the construction of a proposal distribution that is close to the posterior distribution. Recent advances in particle flow filters provide a promising avenue…

Methodology · Statistics 2017-06-30 Yunpeng Li , Mark Coates

We examine some differential geometric approaches to finding approximate solutions to the continuous time nonlinear filtering problem. Our primary focus is a new projection method for the optimal filter infinite dimensional Stochastic…

Probability · Mathematics 2016-01-07 John Armstrong , Damiano Brigo

We consider the problem of constructing quantum operations or channels, if they exist, that transform a given set of quantum states $\{\rho_1, \dots, \rho_k\}$ to another such set $\{\hat\rho_1, \dots, \hat\rho_k\}$. In other words, we must…

Numerical Analysis · Mathematics 2014-07-25 Yuen-Lam Cheung , Dmitriy Drusvyatskiy , Chi-Kwong Li , Diane Pelejo , Henry Wolkowicz

The Quantum Projection Operator-Based NewtonMethod for Trajectory Optimization (Q-PRONTO) is a numerical method for solving quantum optimal control problems. This paper significantly improves prior versions of the quantum projection…

Quantum Physics · Physics 2024-01-10 Jieqiu Shao , Mantas Naris , John Hauser , Marco M. Nicotra

An arbitrary quantum-optical process (channel) can be completely characterized by probing it with coherent states using the recently developed coherent-state quantum process tomography (QPT) [Lobino et al., Science 322, 563 (2008)]. In…

Quantum Physics · Physics 2013-08-09 Xiang-Bin Wang , Zong-Wen Yu , Jia-Zhong Hu , Adam Miranowicz , Franco Nori

We derive an exact equation of motion for the reduced density matrices of individual subsystems of quantum many-body systems of any lattice dimension and arbitrary system size. Our projection operator based theory yields a highly efficient…

Quantum Physics · Physics 2014-06-13 Peter Degenfeld-Schonburg , Michael J. Hartmann

Quantum metrology is a rapidly developing branch of quantum technologies. While various theories have been established on quantum metrology for Markovian processes, i.e., quantum channel estimation, quantum metrology for non-Markovian…

Quantum Physics · Physics 2021-08-04 Anian Altherr , Yuxiang Yang

This study concerns online inference (i.e., filtering) on the state of reaction networks, conditioned on noisy and partial measurements. The difficulty in deriving the equation that the conditional probability distribution of the state…

Methodology · Statistics 2016-11-03 Shinsuke Koyama

Adaptive measurements were recently shown to significantly improve the performance of quantum state tomography. Utilizing information about the system for the on-line choice of optimal measurements allows to reach the ultimate bounds of…

An optimal estimator of quantum states based on a modified Kalman Filter is presented in this work. Such estimator acts after state measurement, allowing to obtain an optimal estimation of quantum state resulting in the output of any…

Quantum Physics · Physics 2014-06-20 Mario Mastriani

Learning low dimensional representation is a crucial issue for many machine learning tasks such as pattern recognition and image retrieval. In this article, we present a quantum algorithm and a quantum circuit to efficiently perform…

Quantum Physics · Physics 2019-03-27 Bojia Duan , Jiabin Yuan , Juan Xu , Dan Li

A fully implementable filtered polynomial approximation on spherical shells is considered. The method proposed is a quadrature-based version of a filtered polynomial approximation. The radial direction and the angular direction of the…

Numerical Analysis · Mathematics 2017-12-27 Yoshihito Kazashi

With nowadays steadily growing quantum processors, it is required to develop new quantum tomography tools that are tailored for high-dimensional systems. In this work, we describe such a computational tool, based on recent ideas from…

Using techniques from semidefinite programming, we study the problem of finding a closest quantum channel to the projection onto a matricial subsystem. We derive two invariants of matricial subsystems which are related to the quantum…

Quantum Physics · Physics 2023-02-28 Roy Araiza , Colton Griffin , Aneesh Khilnani , Thomas Sinclair

We expand the theoretical toolbox for controllable quantum reflection by departing from a simple planar reflector. We introduce a circular hole (a micropore) of variable size, for which the electrostatic image potential can be exactly…

Quantum Physics · Physics 2023-10-06 Romuald Kilianski , Robert Bennett

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