On spurious fixed points in iterative maximum likelihood reconstruction for quantum tomography

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
1. Verfasser: Oberender, Florian
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866912545592311808
author Oberender, Florian
author_facet Oberender, Florian
contents 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 matrix in practice. Contradicting these practical observations, we will show that convergence to a true solution is not guaranteed in general by constructing examples for spurious fixed points. To deal with this newly found problem, we then provide a criterion based on first order optimality conditions to check if the result of the algorithm is indeed the desired solution. Furthermore, we generalize the algorithm and show that it is equivalent to factorized gradient descent.
format Preprint
id arxiv_https___arxiv_org_abs_2508_14549
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On spurious fixed points in iterative maximum likelihood reconstruction for quantum tomography
Oberender, Florian
Quantum Physics
81-08, 81V80, 68W40
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 matrix in practice. Contradicting these practical observations, we will show that convergence to a true solution is not guaranteed in general by constructing examples for spurious fixed points. To deal with this newly found problem, we then provide a criterion based on first order optimality conditions to check if the result of the algorithm is indeed the desired solution. Furthermore, we generalize the algorithm and show that it is equivalent to factorized gradient descent.
title On spurious fixed points in iterative maximum likelihood reconstruction for quantum tomography
topic Quantum Physics
81-08, 81V80, 68W40
url https://arxiv.org/abs/2508.14549