Shaped angular dependence of the spin-transfer torque and microwave generation without magnetic field
By Olivier Boulle, Vincent Cros, Julie Grollier, L. G. Pereira, C. Deranlot, F. Petroff, G. Faini, J. B. sacute, Albert Fert. 2007
148 citations recorded by the source corpus.
The generation of oscillations in the microwave frequency range is one of the most important applications expected from spintronics devices exploiting the spin-transfer phenomenon, which is the reorientation of the magnetization of a ferromagnetic domain by spin-polarized current. Here we report transport and microwave power measurements on specially designed nanopillars, for which a non-standard angular dependence of the spin-transfer torque is predicted by theoretical models. We observe a new kind of current-induced dynamics that is characterized by large angle precessions in the absence of any applied field. This is also predicted by simulations including a ‘wavy’ angular dependence of the torque. This type of nanopillar, which is able to generate microwave oscillations in zero applied magnetic field, could represent an interesting method for the implementation of spin-transfer oscillators. We also emphasize the theoretical implications of our results on the angular dependence of the torque.
Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering
View Paper: https://www.semanticscholar.org/paper/720caca6a83ffed4ef8662d106f36d89b2b030c4
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In Atomic and Molecular Physics, and Optics
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Citations in the corpus
- Nonlinear Auto-Oscillator Theory of Microwave Generation by Spin-Polarized Current (2009, background): “It was, also, shown at first theoretically [46], [47], and then experimentally [48], [49], that in an asymmetric GMR spin valve the microwave generation can be obtained in a zero”
- Electrical Detection of Magnetization Dynamics via Spin Rectification Effects (2016, result): “In general this may not be true [253] with angular dependence appearing explicitly in the conductance and also in non-collinear systems which require a rigorous generalization of the two-current model [252] (which is consistent with a scattering approach”
- Nobel Lecture: Origin, development, and future of spintronics (2008, background): “…possible to obtain very different dynamics with, for applications, the interest of oscillations without applied field by introducing strongly different spin relaxation times in the two magnetic layers of a trilayer to distort the angular dependence of the torque Boulle, 2006; Boulle et al., 2007 .”
- Strong Field Interactions between a Nanomagnet and a Photonic Cavity (2009, background): “Recent progress [109, 110] in the area shows the possibility of generating microwave signals in spin-torque nano-oscillators (STNOs) without applying any external magnetic field.”