Ryan Requist

Ryan Requist

Research Associate

About

Ryan Requist, PhD is a theoretical condensed matter physicist.

First principles calculations of strongly correlated materials, out of equilibrium systems, and solids with unconventional electron-lattice interactions are hindered by a lack of accurate and efficient computational methods. My research introduces new computational tools in condensed matter physics, including tools profiting from differential geometric concepts (in collaboration with Dr. Athanasios Chatzistavrakidis and Dr. Larisa Jonke of the Field Theory and Mathematical Physics Group). The adiabatic approximations we develop make it possible to simulate nonperturbative regimes with greatly reduced computational load.

My PhD student, Fran Dabo, is currently working on energy and charge transport in electron-ion systems and the dynamics of frustrated quantum spin chains (in collaboration with Dr. Fabio Franchini and Dr. Salvatore Marco Giampaolo of the Complex Systems Group).

Ryan is a permanent staff member of the Modelling and Theory of Materials Group since 2024.

Interests
  • Condensed Matter Physics
  • Electronic Structure Theory
Education
  • PhD in Physics, 2005

    Department of Physics and Astronomy | Stony Brook University

2026

1
(2026). Time-dependent density functional theory of electrons and quantum nuclei. Physical Review Letters, in press.
2
(2026). Adiabatic perturbation theory of energy transfer and charge transport in condensed matter. arXiv:2608.13066.
3
(2026). Adiabatically-induced Kawaguchi geometry and jerk in quantum-classical systems. arXiv:2606.16037.
4
(2026). Application of the exact-factorization density-functional perturbation approach to pentacene crystal and monolayer MoS₂. arXiv:2605.11094.

2025

1
(2025). Nonadiabaticity from first principles: Exact-factorization approach for solids. Physical Review B, 112, 075102 (Editors’ Suggestion).
2
(2025). Adiabatic perturbation theory for two-component systems with one heavy component. Physical Review B, 111, 024311.