Oxygen modulated quantum conductance for ultra-thin HfO${}_2$-based memristive switching devices

Abstract

Memristive switching devices, candidates for resistive random access memory technology, have been shown to switch off through a progression of states with quantized conductance and subsequent non-integer conductance (in terms of conductance quantum $G_0$). We have performed calculations based on density functional theory to model the switching process for a Pt-HfO${}_2$-Pt structure, involving the movement of one or two oxygen atoms. Oxygen atoms moving within a conductive oxygen vacancy filament act as tunneling barriers, and partition the filament into weakly coupled quantum wells. We show that the low-bias conductance decreases exponentially when one oxygen atom moves away from interface. Our results demonstrate the high sensitivity of the device conductance to the position of oxygen atoms.

References in corpus (5)

• The SIESTA method for ab initio order-N materials simulation
• Efficient index handling of multidimensional periodic boundary conditions
• Atomic self-interaction correction for molecules and solids
• Observing "Quantized" Conductance Steps in Silver Sulfide: Two Parallel Resistive Switching Mechanisms
• The effect of Ta oxygen scavenger layer on HfO${}_2$-based resistive switching behavior: thermodynamic stability, electronic structure, and low-bias transport

Cited by in corpus (3)

• Dynamic Behaviors and Training Effects in TiN/Ti/HfO${}_x$/TiN Nanolayered Memristors with Controllable Quantized Conductance States: Implications for Quantum and Neuromorphic Computing Devices
• Defect energetics of cubic hafnia from quantum Monte Carlo simulations
• Plane-wave many-body corrections to the conductance in bulk tunnel junctions