The Nanoscale and Quantum Phenomena Institute (NQPI) Seminar Series is pleased to welcome Kishor Nepal, Ohio University, as our featured speaker on Thursday, April 9 at 4:10 p.m. All seminars take place in CLIPPINGER 194 and are also accessible virtually via Teams.

Title: Atomistic Insights into Electronic and Thermal Transport in phase change memory material amorphous Ge2 Sb2Te5

Abstract: Germanium antimony telluride (Ge2Sb2Te5) is a promising phase-change material widely studied for its rapid and reversible transformation between amorphous and crystalline states. Here, we present new insights into the electronic, structural, and transport (thermal and electrical) properties of GST using realistic structural models of Konstantinou et al. [Nat. Commun. 10, 3065 (2019)] within a density functional framework, including hybrid functionals and machine-learned interatomic potentials. We find that Kohn–Sham orbitals near the Fermi level exhibit strong electron–phonon coupling with significant energy fluctuations at room temperature, with conduction tail states showing larger phonon-induced fluctuations than valence tail states. To resolve transport at the atomic scale, we employ space-projected electronic conductivity and site-projected thermal conductivity, revealing spatially heterogeneous transport dominated by filamentary networks primarily composed of Te, with progressively smaller contributions from Sb and Ge.