2020/05/27 by Jan Albert, Ferran Macià, J. M. Hernández +1 · 8 citations
Engineering · Physics and Astronomy · #Amplitude #Condensed matter physics #Dissipation #Excitation #Magnetic field #Magnetic properties of thin films #Magnetization #Magnetization dynamics #Magneto-Optical Properties and Applications #Magnetoresistance #Materials science #Physics #Quantum and electron transport phenomena #Quantum mechanics #Spin (aerodynamics) #Torque #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.102.184421
published in Physical review. B./Physical review. B 102(18) (American Physical Society)
arxiv created 2020/05/27 · openalex created_date 2020/06/05 · openalex publication_date 2020/11/18 · arxiv updated 2020/11/25 · openalex updated_date 2026/08/05
Spin-torque nano-oscillators (STNO) are microwave auto-oscillators based on magnetic resonances having a nonlinear response with the oscillating amplitude, which provides them with a large frequency tunability including the possibility of mutual synchronization. The magnetization dynamics in STNO are induced by spin-transfer torque (STT) from spin currents and can be detected by changes in electrical resistance due to giant magnetoresistance or tunneling magnetoresistance. The STT effect is usually treated as a dampinglike term that reduces magnetic dissipation and promotes excitation of magnetic modes. However, an additional term, known as Zhang-Li term, has an effect on magnetization gradients such as domain walls, and could have an effect on localized magnetic modes in STNO. Here we study the effect of Zhang-Li torques in magnetic excitations produced in STNO with a nanocontact geometry. Using micromagnetic simulations we find that Zhang-Li torques modify threshold currents of magnetic modes and their effective sizes. Additionally, we show that effects can be controlled by changing the ratio between nanocontact size and layer thickness.