Graphene node with filtered electron spin Conceptual map: The blue nickel layer and the red iron layer contain two spin states (spin and spin) electrons. Layers of graphene (graphene, a quasi-two-dimensional plane of single-layer carbon atoms) are placed between two thin metal films to form a conductive path that allows only one direction-spinned electron to pass through. After the current through the metal junction, it becomes a spin-polarized current. Show Source: US Navy Laboratory NRL Graphene has an unusual history in the history of spintronics (also known as magnetoelectronics). The electronics use the electron's own spin state for information encoding, rather than the traditional use of the electron's own charge to encode. Initially, graphene did not appear in the field of vision. Because when the electron through the plane of the graphene after the spin state without any change, and the direction of the electron is still random, and did not form a certain path. However, as far as I know, a recent experimental result shows that graphene may have a great effect on spintronics, which also changed the view of research project managers. A team from the U.S. Naval Laboratory (NRL) recently conducted an experiment where they placed a layer of graphene in layers of nickel and iron. This laminated structure, for the first time at room temperature can be filtered electron spin film-like nodes. This result may be of great help in the development of next generation Magnetoresistive Random Access Memory (MRAM). The principle of MRAM is to use the pulse after spin polarization, turn the magnetic information of the storage bit from 0 to 1, and also reverse flip. Spin-filtering This phenomenon makes it possible to obtain highly spin-polarized carriers. In fact, the principle of such a device is the same as that of a filter, which allows only electrons of one spin direction to pass and impedes electrons of another spin direction. This allows the electronic "up" and "down" spin to be distinguished, forming "0" and "1" in the digital logic. In this laminated structure, the spin-filtration phenomenon is caused by the interaction of the quantum mechanical properties of the graphene and the crystalline nickel film. After alignment of the nickel and graphene layers, this configuration allows only one specific spin-direction electron to flow from the material to the other. "This type of spin-filtering was previously theoretically predicted, but only previously proved to be effective in cryogenic high-impedance structures," said Dr. Enrique Cobas, principal investigator at NRL Materials Science and Technology, at a conference call. "The new results confirm that this effect (spin-filtering) can also exist in the low-resistance structure of multiple device matrices at room temperature." In the ACS Nano paper, researchers at NRL are investigating the conductivity and the interaction with graphene after lamination. To this end, NRL's team has created a new way to make large, multilayer graphene films directly on a flat, crystalline nickel-alloy film. This method maintains the magnetic properties of the nickel alloy films so that they can be arranged as switching matrix junctions. "We still have room for improvement, because by theoretically fine tuning the layers of graphene, this effect can be enhanced by an order of magnitude," said Dr. Olaf van't Erve, a researcher at NRL Materials Science and Technology at a conference. . "However, the current model does not include the spin transitions that occur during ferromagnetic contact and when we take those effects into account we can really approximate the ideal of 100% spin polarization, We modify and optimize the current equipment construction and materials to maximize the effect. "