arXiv subjects

Peter Schaaf

Publications and source records attributed to Peter Schaaf.

3 recordsLinked to original sources

arXiv2026

End-to-End Modeling of a Volatile TiO2 Memristor for Neuromorphic Circuit Simulation

Memristors are promising devices for applications such as non-volatile memory, neuromorphic computing, logic circuits, and analog signal processing. The development of such systems requires accurate simulations based on models that reproduce the electrical behavior of real devices under both continuous and pulsed excitation. This work presents the development of a simulation environment for a volatile TiO2-based memristor. Experimental measurement data are analyzed to verify the memristive behavior of the device and to identify a suitable model. The model parameters are then optimized to match the measured characteristics. The resulting model is implemented in SPICE and validated by comparing simulation results with measurement data. The comparison shows a good agreement between simulation and experiment, demonstrating that the developed model is suitable for reproducing the electrical behavior of the investigated memristor and can be applied in circuit-level simulations, as demonstrated by a leaky integrate-and-fire neuron.

cond-mat.mtrl-sci↗

arXiv2020

Metastable atomic layer deposition: 3D self-assembly towards ultra dark materials

Black body materials prove promising candidates to meet future energy demands as they are able to harvest energy from the total bandwidth of solar radiation. Here, we report on high absorption (> 98 %) near-black body-like structures consisting of a silica scaffold and Ag nanoparticles with a layer thickness below 10 um; fabricated using metastable atomic layer deposition (MS-ALD) and to be applied for a wide solar spectrum ranging from 220 nm to 2500 nm. Several effects contribute collectively and in a synergistic manner to the high absorbance, including the pronounced heterogeneity of the nanoparticles in size and shape, particle plasmon hybridization and the trapping of omni-directionally scattered light in the 3D hierarchical hybrid structures. We propose that, in the future, MS-ALD needs to be considered as a simple and promising method to fabricate black-body materials with excellent broadband absorption.

cond-mat.mtrl-sci↗

arXiv2018

Strong spatial and spectral localization of surface plasmons in individual randomly disordered gold nanosponges

Porous nanosponges, percolated with a three-dimensional network of 10-nm sized ligaments, recently emerged as promising substrates for plasmon-enhanced spectroscopy and (photo-)catalysis. Experimental and theoretical work suggests surface plasmon localization in some hot-spot modes as the physical origin of their unusual optical properties, but so far the existence of such hot-spots has not been proven. Here we use scattering-type scanning near-field nano-spectroscopy on individual gold nanosponges to reveal spatially and spectrally confined modes with 10 nanometer localization lengths by mapping the local optical density of states. High quality factors of individual hot-spots of more than 40 are demonstrated. A statistical analysis of near-field intensity fluctuations unveils plasmonics in the strong localization regime. The observed field localization and enhancement make such nanosponges an appealing platform for a variety of applications ranging from nonlinear optics to strong-coupling physics.

cond-mat.mes-hall↗