Abstract:
Techniques, systems, and devices are disclosed for implementing a quasi-linear spin-torque nano-oscillator based on exertion of a spin-transfer torque on the local magnetic moments in the magnetic layer and precession of the magnetic moments in the magnetic layer within a spin valve. Examples of spin-torque nano-oscillators (STNOs) are disclosed to use spin polarized currents to excite nano magnets that undergo persistent oscillations at RF or microwave frequencies. The spin currents are applied in a non-uniform manner to both excite the nano magnets into oscillations and generate dynamic damping at large amplitude as a feedback to reduce the nonlinearity associated with mixing amplitude and phase fluctuations.
Abstract:
La présente invention concerne un oscillateur (30) à transfert de spin comportant un empilement magnétique (E) incluant au moins deux couches magnétiques (32,34) dont au moins une desdites deux couches magnétiques, dite couche oscillante (32), a une aimantation de direction variable et des moyens d'alimentation (31, 35) en courant aptes à faire circuler un courant d'électrons perpendiculairement au plan dudit empilement magnétique (E). L'empilement magnétique (E) comportant des moyens (33) aptes à générer des inhomogénéités de courant au niveau de la surface de ladite couche oscillante et l'intensité de courant fourni par lesdits moyens d'alimentation (31, 35) est choisie de sorte l'aimantation de ladite couche oscillante présente une configuration magnétique cohérente, ladite configuration magnétique oscillant dans son ensemble à une même fréquence fondamentale.
Abstract:
Cet ocillateur radiofréquence intégre : - un dispositif magnétorésistif (6) à base d'un courant électrique polarisé en spin pour générer un signal oscillant à une fréquence d'oscillation sur une borne (10) de sortie, et - une borne (18) de commande de la fréquence ou de l'amplitude du signal oscillant, et - une boucle (44) de rétroaction comportant un amplificateur (46) équipé : - d'une entrée raccordée à la borne (10) de sortie du dispositif magnétorésistif (6) de manière à amplifier la partie d'un signal oscillant captée au niveau de la borne de sortie, et - d'une sortie raccordée à la borne (18) de commande de manière à injecter sur cette borne de commande la partie amplifiée du signal oscillant en phase avec le signal oscillant généré sur la borne de sortie.
Abstract:
A frequency sensor is provided. The frequency sensor may include: a magnetoresistive nano-oscillator including a magnetic heterostructure of at least a magnetic free layer, a magnetic reference layer and a non-magnetic intermediate layer arranged between the magnetic free layer and the magnetic reference layer; a coupling arrangement for coupling an incoming signal to at least one magnetic mode of the magnetic free layer, and a frequency estimator. The frequency estimator may be configured to: perform a plurality of voltage measurements across the magnetoresistive nano-oscillator over time; calculate a time averaged voltage across the magnetoresistive nano-oscillator based on the plurality of voltage measurements; estimate, over a finite range of frequencies, a frequency of the incoming signal based on the calculated time averaged voltage, and output a signal representative of the estimated frequency. A method of estimating a frequency of an incoming signal is also provided.
Abstract:
A spin oscillator device (NCI) comprising a first spin torque oscillator, STO (2), having an extended multilayered magnetic thin-film stack (2), wherein a nano-contact, NC, (6) is provided on said magnetic film stack (2) providing an NC-STO (2, 6) comprising a magnetic free-layer (3) and having a nanoscopic region, wherein the NC (6) is configured to focus electric current (I de ) to the nanoscopic region, configured to generate the necessary current densities needed to excite propagating spin waves (SWs) in the magnetic free layer (3), wherein a circumferential magnetic field (H Oe ) surrounds the NC (6), wherein an externally applied field (H ext ) is configured to control the control the propagation of the spin waves (SWs) forming a spin wave beam (SW beam) to a second spin oscillator device (NCn), which is arranged in spin wave communication and synchronized to the first NCI.
Abstract:
Described is an apparatus which comprises: a magnetic junction device having a magnetic layer with in-plane anisotropy and a magnetic layer with perpendicular anisotropy; a spin orbit coupling (SOC) layer coupled to the magnetic junction device; a first non-magnetic conductor coupled to one end of the SOC layer; a second non-magnetic conductor coupled to another end of the SOC layer; a third non-magnetic layer coupled to the magnetic junction device; and a bias T network coupled to the third non-magnetic layer.