The Department of Mathematical Foundations of Informatics

is organizing a seminar under the project

„Strategies for improving the quality of models identified by machine learning algorithms with application in quantum tomography“.

A talk will be delivered by

Violeta Ivanova-Rohling and Niklas  Rohling

on:

Quantum state tomography as a numerical optimization problem

Abstract: We present a framework that formulates the quest for the most efficient quantum state tomography scheme as an optimization problem which can be solved numerically. This approach can be applied to a broad spectrum of relevant setups including measurements restricted to a subsystem. To illustrate the power of this method we present results for the six-dimensional Hilbert space constituted by a qubit-qutrit system, which could be realized e.g. by the N-14 nuclear spin-1 and two electronic spin states of a nitrogen-vacancy center in diamond. Measurements of the qubit subsystem are expressed by projectors of rank three, i.e., projectors on half-dimensional subspaces. For systems consisting only of qubits, it was shown analytically that a set of projectors on half-dimensional subspaces can be arranged in an informationally optimal fashion for quantum state tomography, thus forming so-called mutually unbiased subspaces. Our method goes beyond qubits-only systems and we find that in dimension six such a set of mutually-unbiased subspaces can be approximated with a deviation irrelevant for practical applications.

The seminar will be held on March 30, 2021 (Tuesday), at 6:00 pm in Zoom.

Join Zoom Meeting
https://us02web.zoom.us/j/89537593729?pwd=Wm9LYmhNeEZ5YlNkaGQvblNwMnlZdz09

Meeting ID: 895 3759 3729
Passcode: 021763