Modeling Spin Dynamics: The Interaction Between Positive Muons and Quadrupolar Nuclei

by Michael Penkov (Berlinger & Co AG, formerly Uni Oxford)

Thursday 26 Jun 2025, 09:30 → 10:30 Europe/Zurich

ODRA/111

In this talk, I will present a numerical approach to studying quantum spin systems with relevance to muon spin spectroscopy. The core of the project is a program designed to construct and diagonalize the Hamiltonian of a spin system with arbitrary composition, incorporating various interactions such as spin-spin coupling, Zeeman and dipolar effects, and quadrupolar interactions. Using this tool, we simulate time-dependent polarization dynamics of embedded particles, with a focus on positive muons. Applying the model to an antimuon in a copper lattice, we reproduce key experimental observations such as an avoided energy-level crossing at ~8 mT. Further parameter studies show how quadrupolar and dipolar coupling constants influence both the position and shape of polarization dips in magnetic field scans. These results illustrate the power of computational modeling in exploring and interpreting complex spin interactions in condensed matter systems.