Scalable synchronization of spin-Hall oscillators in out-of-plane field

Abstract

A strategy for a scalable synchronization of an array of spin-Hall oscillators (SHOs) is illustrated. In detail, we present micromagnetic simulations of two and five SHOs realized by means of couples of triangular golden contacts on the top of a Pt/CoFeB/Ta trilayer. Results highlight that the synchronization occurs for the whole current region that gives rise to the excitation of self-oscillations. This is linked to the role of the magnetodipolar coupling, which is the phenomenon driving the synchronization when the distance between oscillators is not too large. Synchronization turns out to be also robust against geometrical differences of the contacts, simulated by considering variable distances between the tips ranging from 100nm to 200nm. Besides, it entails an enlargement of the radiation pattern that can be useful for the generation of spin-waves in magnonics applications. Simulations performed to study the effect of the interfacial Dzyaloshinskii-Moriya interaction show nonreciprocity in spatial propagation of the synchronized spin-wave. The simplicity of the geometry and the robustness of the achieved synchronization make this design of array of SHOs scalable for a larger number of synchronized oscillators. a)

Micromagnetic modeling of terahertz oscillations in an antiferromagnetic material driven by the spin Hall effect

“…THz sources can be realized with quantum cascade lasers [11], solid state devices [12], however the development of compact nano-sized electrical generators and receivers of THz signals represents a key-challenge of the modern technology. With the experience maturated after decades of research on the generation and manipulation of GHzfrequency dynamics in ferromagnetic materials [13,14,15,16,17,18], development of high quality AFM materials for several applications [19,20,21,22,23], and proof of concept of antiferromagnetic memories [24,25,26,27] driven by the spin-Hall effect (SHE) [28], research is now combining this know-how focusing on the development of AFM-based oscillators for application in 4G and 5G telecommunication systems [29,30,31,32,33,34,35]. Up to now, there is no experimental proof of AFM-based oscillators (ASHO), and all the theoretical studies are considering two sub-lattices with their magnetizations antiferromagnetically coupled [36] and their dynamics is studied by solving two Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equations [37] within the macrospin approximation [29,31,32].…”

Configurational entropy of magnetic skyrmions as an ideal gas

“…Platinum. We perform systematic micromagnetic simulations to calculate the skyrmion sizes as a function of the out-of-plane external field 0Hext and temperature T, by integrating the Landau-Lifshitz-Gilbert equation for the reduced magnetization s M / M m  [42][43][44][45][46][47][48] ( s M is the saturation magnetization, see note 1 in the Supplemental Material). At T=0 K, we used the following material parameters: s M =600 kA/m [12], A =20 pJ/m [49], D =3.0 mJ/m 2 [50,51], u K =0.60 MJ/m 3 [12,52], and Gilbert damping G  =0.1 [53], while for T>0 and the analytical model, we used the parameters as calculated from the scaling relations [35] …”

Correction of Phase Errors in a Spin-Wave Transmission Line by Nonadiabatic Parametric Pumping

“…To confirm our theoretical predictions about the SW phase stabilization we performed a series of micromagnetic simulations using the GPMagnet solver [34,35]. In our simulations the SWs were excited linearly by a microwave magnetic field applied at the excitation gate of the length L e = 50 nm.…”