Resistive switching in SiOx (B.Sc. thesis, BME, 2024 to 2026)
My thesis is how a thin SiOx film switches resistance when current is applied (what structural change and physical laws explain the change most accurately and predict the empirically measured noise spectrum).
1. resistor-network models for that noise
(a) a static Kirchhoff network on vacancy sites, with trap-assisted tunneling conductances, fitted against empirical noise data
(b) a dynamic layer on the same graph, kinetic Monte Carlo with field-driven vacancy motion and Joule heating, to see which filament configurations actually survive under bias
2. atomistic simulations to supply the geometry
I used the LAMMPS framework (C++-based molecular dynamics library) with machine-learned interatomic potentials: an ACE (atomic cluster expansion) Si–O model to melt-quench amorphous SiOx with controlled oxygen deficiency, avoiding the spurious silicon nanowire artifact that older reactive force fields (like ReaxFF) tend to produce
we used the generated vacancy positions from those cells and fed them into the networks in (1)