arXiv subjects

Rutger Duflou

Publications and source records attributed to Rutger Duflou.

4 recordsLinked to original sources

arXiv2024

Fully coupled electron-phonon transport in two-dimensional-material-based devices using efficient FFT-based self-energy calculations

Self-heating effects can significantly degrade the performance in nanoscale devices. We investigate self-heating effects in such devices based on two-dimensional materials using ab-initio techniques. A new algorithm was developed to allow for efficient self-energy computations, achieving a $\sim$500 times speedup. It is found that for the simple case of free-standing MoS$_2$ without explicit metal leads, the self-heating effects do not result in significant performance degradation.

cond-mat.mes-hall↗

arXiv2021

Advanced DFT-NEGF transport techniques for novel 2D-material and device exploration including HfS2/WSe2 van-der-Waals Heterojunction TFET and WTe2/WS2 metal/semiconductor contact

We present, here, advanced DFT-NEGF techniques that we have implemented in our ATOmistic MOdelling Solver, ATOMOS, to explore transport in novel materials and devices and in particular in van-der-Waals heterojunction transistors. We describe our methodologies using plane-wave DFT, followed by a Wannierization step, and linear combination of atomic orbital DFT, that leads to an orthogonal and non-orthogonal NEGF model, respectively. We then describe in detail our non-orthogonal NEGF implementation including the Sancho-Rubio and electron-phonon scattering within a non-orthogonal framework. We also present our methodology to extract electron-phonon coupling from first principle and include them in our transport simulations. Finally, we apply our methods towards the exploration of novel 2D materials and devices. This includes 2D material selection and the Dynamically-Doped FET for ultimately scaled MOSFETS, the exploration of vdW TFETs, in particular the HfS2/WSe2 TFET that could achieve high on-current levels, and the study of Schottky-barrier height and transport through a metal-semiconducting WTe2/WS2 VDW junction transistor.

cond-mat.mes-hall↗

arXiv2017

Strain coupling optimization in magnetoelectric transducers

The mechanical behavior of magnetoelectric transducers consisting of piezoelectric-magnetostrictive bilayers has been modeled. The effect of the aspect ratio of the transducer as well as the influence of non-active surrounding layers has been modeled, including a passivation layer surrounding the active device, a clamping layer above the active device, and an interfacial layer that might be inserted between the magnetostrictive and the piezoelectric layers. Strategies to control and maximize the strain magnitude and orientation based on material selection and device design are proposed.

physics.app-ph↗

arXiv2017

Micromagnetic simulations of magnetoelastic spin wave excitation in scaled magnetic waveguides

We study the excitation of spin waves in scaled magnetic waveguides using the magnetoelastic effect. In uniformly magnetized systems, normal strains parallel or perpendicular to the magnetization direction do not lead to spin wave excitation since the magnetoelastic torque is zero. Using micromagnetic simulations, we show that the nonuniformity of the magnetization in submicron waveguides due to the effect of the demagnetizing field leads to the excitation of spin waves for oscillating normal strains both parallel and perpendicular to the magnetization. The excitation by biaxial normal in-plane strain was found to be much more efficient than by uniaxial normal out-of-plane strain. For narrow waveguides with widths of 200\,nm, the excitation efficiency of biaxial normal in-plane strain was comparable to that of shear strain.

cond-mat.mes-hall↗