Reducing the switching current with a Gilbert damping constant in nanomagnets with perpendicular anisotropy

Abstract

We report on current-induced magnetization switching in a nanomagnet with perpendicular anisotropy, and investigate the effects of the damping constant (α) on the switching current (Isw) by varying the nanosecond-scale pulse current duration (tp), the saturation magnetization (Ms), and the magnetocrystalline anisotropy (Ku). The results show that reduction of α below a certain threshold (αc) is ineffective in reducing Isw for short tp. When tp is short, it is necessary to reduce both α and Ms simultaneously until αc is reached to reduce Isw. The results presented here offer a promising route for the design of ultrafast information storage and logic devices using current-induced magnetization switching.

Effects of Recirculating Aquaculture System Wastewater on Anammox Performance and Community Structure

“…For example, Actinomarinales with opportunistic copiotrophic lifestyles may experience the presence of particulate organic matter as an advantageous micro-heterogeneity [54]. Chloroflexi can fermentatively utilize sugars and protein compounds [55], and Bacteroidetes are polysaccharide-degrading bacteria, highly successful competitors in gut ecosystems [56]. OM190 and Ulvibacter are both strictly aerobic [57,58].…”

Respective influence of in-plane and out-of-plane spin-transfer torques in magnetization switching of perpendicular magnetic tunnel junctions

“…Nominal 50-nm-diameter pMTJ pillars were fabricated from an MTJ stack grown by magnetron sputtering. The stack contains a 1.7-nm-thick Co 20 TMR = 126%. The second MgO barrier was introduced to increase the perpendicular anisotropy of the free layer.…”

“…Thermal activation mainly decreases the threshold current value and the switching time, introducing an undesirable stochastic magnitude effect in both parameters [16,17]. The influence of the writing pulse duration was also theoretically studied [16,[18][19][20][21].…”

Perpendicular magnetic tunnel junction with a strained Mn-based nanolayer

“…Currently, Co-Fe-B alloy and its derivatives are widely used for p-MTJs because they possess high spin-polarisation, which leads to a large TMR effect 9 10 . However, the alloy’s large saturation magnetisation of approximately 1000 emu/cm 3 , which results from the main constituents of Fe-Co, makes the p-MTJs difficult to integrate with higher density and faster writing speed 8 11 . In addition, its perpendicular magnetic anisotropy (PMA), which originates from the MgO/Co-Fe-B interface, with a typical value of 1–2 Merg/cm 3 , is not large enough to retain the magnetisation direction against thermal fluctuation when the p-MTJ size is reduced to 10–20 nm 8 .…”