You are cordially invited to the SCL online seminar of the Center for the Study of Complex Systems, which will be held on Thursday, 26 May 2022 at 14:00 on Zoom. The talk entitled

Fully-atomistic simulations of valence change memories

will be given by Dr. Marko Mladenović (Integrated Systems Laboratory, ETH Zurich, Switzerland). Abstract of the talk:

The ability to vary their conductance makes valence change memories (VCMs) promising candidates for applications in emerging neuromorphic applications [1]. The operational mechanism of VCMs is based on the arrangement of oxygen vacancies in the presence of applied voltage: if a conductive path consisting of oxygen vacancies is established between two electrodes, the VCM is in its low resistance (ON) state, if the conductive path is broken, the system is in its high resistance (OFF) state. In this talk, a theoretical framework to model VCMs will be presented. The model is fully-atomistic and consists of three steps: (1) calculating the activation energies for events that occur in VCMs using density functional theory calculations; (2) simulating the rearrangement of oxygen vacancies using an in-house kinetic Monte Carlo code; and (3) calculating the transport properties using the quantum transport method based on non-equilibrium Green’s function formalism. Following a detailed description of the method, an overview of the results on hafnium oxide-based VCMs will be given.

[1] K.Portner et al, ACS Nano 15, 14776 (2021).

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