Tommy Chin: Theoretical Physics, Open Quantum Systems

Tommy Chin

PhD Candidate in Physics

Institute for Gravitation & the Cosmos, The Pennsylvania State University

I develop theoretical frameworks for open quantum systems that infer global properties of a system from ensembles of local subsystem descriptions, with emphasis on correlations, non-Markovian dynamics, and quantum Fisher information.

Research

I am a PhD candidate in theoretical physics at the Pennsylvania State University, working with Prof. Sarah Shandera in the Institute for Gravitation and the Cosmos. My research is in the theory of open quantum systems: how information, excitation, and correlations move through quantum networks whose subsystems are coupled to environments that can never be directly observed.

Using excitation flow, positivity constraints, quantum Fisher information, and propagators, I study what can and cannot be inferred about a quantum system from partial, local observations. These questions are motivated by foundational problems in physics, particularly in cosmological and high-energy settings, where observation is fundamentally limited to partial access to correlated subsystems of a larger quantum system.

I am on the academic job market for postdoctoral positions in theoretical physics and open quantum systems, starting Fall 2028.

Publications

A fully connected N-qubit network partitioned into four open subsystems, each described by a reduced density matrix.

2026 · Preprint

Excitation Flow, Positivity, and Fisher Information for Open Subsystems of an N-Qubit Network

T. Chin, S. Shandera

arXiv:2605.15036 [quant-ph] (2026)

arXiv

Eigenvalue distributions in the unit disk for phase-covariant versus non-phase-covariant qubit ensembles.

2024 · Peer-reviewed

Effective Dynamics of Qubit Networks via Phase-Covariant Quantum Ensembles

S. Prudhoe, U. Akhouri, T. Chin, S. Shandera

Open Systems & Information Dynamics 31, 2450016 (2024)

DOI arXiv

A 3 by 3 array of cubes showing strain and dark-state orientation configurations for silicon-vacancy centers.

In preparation

Impact of Strain and Dark States on Spectroscopic Measurements of Silicon-Vacancy Centers in Diamond

T. Chin, K. Bates, C. Smallwood

Manuscript in preparation

Selected Talks

Apr 2026Invited talk, Open Quantum Systems: Dissipation and Decoherence from Subatomic to Cosmic Scales, Mainz Institute for Theoretical Physics (MITP), Johannes Gutenberg University Mainz.

Nov 2025“Ensembles of Propagators, Not Single Hamiltonians, Govern Open Quantum Dynamics,” APS Mid-Atlantic Section Meeting 2025, Penn State Harrisburg.

Jul 2025“Relative Correlations, Not Initial States, Govern Positivity in Open Quantum Dynamics,” Quantum Gravity 2025, Institute for Gravitation & the Cosmos, Penn State.

Oct 2025“Open Quantum Systems via Dynamical Maps,” Primordial Universe & Gravity Seminar, IGC, Penn State.

Sep 2024“Open Quantum Systems via Dynamical Maps,” Colloquium, Department of Physics & Astronomy, San José State University.

A full list of talks and posters, including the “Entropy Whisperer” poster award (University of Rochester, 2026), is in the CV.

Honors & Awards

2024–2026W. Donald Miller Graduate Fellowship, Penn State

2024–2025David C. Duncan Graduate Fellowship, Penn State

2022–2025Verne M. Willaman Distinguished Graduate Fellowship, Penn State

2024NSF Graduate Research Fellowship, Honorable Mention

2022–2023Nellie H. and Oscar L. Roberts Graduate Fellowship, Penn State