Physics & Astronomy ETDs

Publication Date

Spring 5-16-2026

Abstract

Nonclassicality in quantum sensors can improve sensitivity, but often increases susceptibility to noise. Thus, modeling physically relevant noise sources and analyzing their effect on quantum metrology are both of importance to the field of quantum sensing. In this dissertation, I demonstrate that local noise sources, which are present in almost all many-spin systems, can be tractably modeled when assuming permutation symmetry of the noise, and we show that many common local noise sources can be mapped to a Fokker-Planck equation on quantum phase space. We apply this description of noise to study quantum sensing using noisy probe states and establish a previously unknown connection between loss of Fisher information for noisy states and discontinuities in the Fisher information as a function of a continuous family of measurements. Finally, we extend the phase space description of local noise by developing a new spin Wigner function, which we call the solid spin Wigner function. We develop this new Wigner function by noting that the permutationally symmetric operator space used to describe symmetric local noise resembles the symmetric subspace of an ensemble of SU(3) particles. Using this, it is possible to embed the SU(2) group structure of the spin ensemble within this larger group, and describe the system using an SU(3) Wigner function.

Degree Name

Physics

Level of Degree

Doctoral

Department Name

Physics & Astronomy

First Committee Member (Chair)

Ivan H. Deutsch

Second Committee Member

Akimasa Miyake

Third Committee Member

Francisco Elohim Becerra

Fourth Committee Member

Milad Marvian

Language

English

Keywords

sensing, metrology, quantum, information, Wigner function, noise, modeling, phase space

Document Type

Dissertation

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