arXiv subjects

Christian Engel

Publications and source records attributed to Christian Engel.

3 recordsLinked to original sources

arXiv2026

Adaptive algorithm for microsensor in sustainable environmental monitoring

Traditional data collection from sensors produce a lot of data, which lead to constant power consumption and require more storage space. This study proposes an algorithm for a data acquisition and processing method based on Fourier transform (DFT), which extracts dominant frequency components using harmonic analysis (HA) to identify frequency peaks. This algorithm allows sensors to activate only when an event occurs, while preserving critical information for detecting defects, such as those in the surface structures of buildings and ensuring accuracy for further predictions.

eess.SP↗

arXiv2017

Quantification of spin accumulation causing spin-orbit torque in Pt/Co/Ta stack

Spin accumulation induced by spin-orbit coupling is experimentally quantified in stack with in-plane magnetic anisotropy via the contribution of spin accumulation to Hall resistances. Using a biasing direct current the spin accumulation within the structure can be tuned, enabling quantification. Quantification shows the spin accumulation can be more than ten percentage of local magnetization, when the electric current is 1E11 A/m*m. The spin accumulation is dependent of the thickness of Ta layer, the trend agrees with that of spin Hall angle indicating the capability of Ta and Pt in generating spins.

cond-mat.mes-hall↗

arXiv2017

Quantitative characterization of spin-orbit torques in Pt/Co/Pt /Co/Ta/BTO heterostructure on the magnetization azimuthal angle dependence

Substantial understanding of spin-orbit interactions in heavy-metal (HM)/ferromagnet (FM) heterostructures is crucial in developing spin-orbit torque (SOT) spintronics devices utilizing spin Hall and Rashba effects. Though the study of SOT effective fields dependence on the out-of-plane magnetization angle has been relatively extensive, the understanding of in-plane magnetization angle dependence remains unknown. Here, we analytically propose a method to compute the SOT effective fields as a function of the in-plane magnetization angle using harmonic Hall technique in perpendicular magnetic anisotropy (PMA) structures. Two different samples with PMA, Pt/Co/Pt/Co/Ta/BaTiO3 (BTO) test sample and Pt/Co/Pt/Co/Ta reference sample are studied using the derived formula. Our measurements reveal that only the dampinglike field of the test sample with BTO capping layer exhibits an in-plane magnetization angle dependence while no angular dependence is found in the reference sample. The presence of the BTO layer in the test sample, which gives rise to a Rashba effect at the interface, is ascribed as the source of the angular dependence of the the dampinglike field.

cond-mat.mtrl-sci↗