Date of Award
Spring 2026
Language
English
Embargo Period
5-10-2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
College/School/Department
Department of Physics
Program
Physics
First Advisor
Philip Goyal
Committee Members
Philip Goyal, Jesse Ernst, Daniel Robbins, Jonathan Petruccelli, Rongwei Yang
Keywords
Quantum Measurements, Quantum State Tomography, Information Theory, POVM Measurements
Subject Categories
Quantum Physics
Abstract
This thesis will focus on deriving informationally-optimal quantum state tomographic measurements on single-qubit systems, with the definition of informationally optimal to be defined as those measurements which maximize the average information gain. The informationally-optimal measurements that will be covered include projective measurements (formally building off of the work of [1] and putting it on firm, information-theoretic foundations), and more general types of quantum measurements called directional (also known as rank-one) positive operator-valued measure (POVM) measurements, and, finally, adaptive directional POVM measurements.
For projective measurements, we build on the work of Wootters and Fields ([1]) and show, via analytical methods and maximizing the average information gained from the measurements, that orthogonal projective measurements are optimal.
We then go on to define what we call directional POVMs, which are POVMs whose elements are given by weighted projection operators. We consider these measurements in the context of static quantum state tomography (QST), wherein we use the same choice of measurement throughout our analysis/experiment. By examining these directional POVMs acting on single qubit systems, we show that the most informationally optimal of these types of measurements are informationally complete directional POVMs that are both minimal, informationally complete (MIC) and symmetric, informationally complete (SIC) POVMs, simultaneously.
Finally, we deal with the case of adaptive directional POVM measurements.
License
This work is licensed under the University at Albany Standard Author Agreement.
Recommended Citation
Preston, Adam V., "Informationally-Optimal Measurements on Single-Qubit Systems" (2026). Electronic Theses & Dissertations (2024 - present). 476.
https://scholarsarchive.library.albany.edu/etd/476