The studies on the magnetization dynamics of spintronics nanodevices is one of the main activities of SPINTEC, carried out within the group of «Microwave Devices ». The spin polarized transport properties allow one to conceive a nano-oscillator (size 100nm) that emits in the range of 0.2-20 GHz: by injecting a DC current an AC voltage is generated. The advantage of these nano-oscillators is their small size (compactness), their frequency tunability (via the DC current), their fast commutation between frequencies (ns), their multifunctionality (generation, modulation and detection). Since ~10 years SPINTEC realises (magnetic thin film deposition and nanofabrication) and studies these spintronics nano-oscillators. The fundamental aspect of this work aims at the understanding of the non-linear dynamic properties in relation to the spin polarized transport properties, while the applicative aspect aims at the understanding and improvement of the two most important parameters which are the output signal amplitude, that needs to be enhanced, as well as the phase noise, that needs to be reduced. SPINTEC has been coordinator of the Europeen project MOSAIC (1/1/2013 – 31/12/2016), that aimed at (i) improving the performances by exploring different coupling schemes (within the magnetic layers, between devices and to an external source) and at (ii) a first realization of rf circuits to demonstrate the « integrability » of these oscillators. PLL operation for oscillators emitting in the 0.2 – 0.8 GHz range was demonstrated with a reduction of phase noise of several decades (at f=100kHz). A second circuit concerns the realization of an FSK communication scheme (for wireless sensor networks). The exploitation of the results in the frame of a new EC project is under discussion.
In the frame of two other EC projects, coordinated by SPINTEC (general spintronics applications for memory, mogic, sensor and rf functions) explores different magnetic configurations for frequency generation.
Contact FIRST-TF: Ursula EBELS, ursula.ebels(at)cea.fr