Multi-state memory, preparation method and storage method thereof and artificial synaptic device

Abstract

The invention discloses a multi-state memory, a preparation method and a storage method thereof and an artificial synaptic device. The multi-state memory is provided with a multi-layer thin film structure and sequentially comprises a spin current generation layer, a first exchange bias layer, an insulating material layer, a second exchange bias layer and an upper electrode from bottom to top, wherein the spin current generation layer is used for generating a spin current for applying a spin orbital moment to a magnetic moment; the first exchange bias layer is used for storing data; the insulating material layer is used for providing vertical magnetic anisotropy; the second exchange bias layer is used for reading the tunneling magnetoresistance; a first electrode and a second electrode arearranged at the two ends of the spin current generation layer respectively, and a write current is applied between the first electrode and the second electrode to store data; and a read current is applied between the second electrode and the upper electrode to read data. The storage density and the storage stability of the multi-state memory are effectively improved, the storage power consumptionis reduced, and the anti-interference capability of the memory is improved.

Description

technical field [0001] The invention relates to information storage and semiconductor fields, in particular to a multi-state memory based on two exchange bias layers composed of antiferromagnetic and ferromagnetic materials, its preparation method, multi-state storage method and artificial synapse. Background technique [0002] With the rapid development of the information age, the era of big data has come, which requires increasing the data storage density of the current memory, so polymorphic storage has been widely studied. Compared with traditional computer binary storage, polymorphic storage realizes the storage of multiple bytes in one storage unit, which can greatly increase the information storage density. On the other hand, although the computer based on the "von Neumann" configuration shows great advantages in data calculation, it is far behind the human brain in terms of image recognition and learning ability; Under the circumstances, the power consumption of the...

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Problems solved by technology

For a single antiferromagnetism, although the multistate storage function can be realized, and the storage state is very stable, but because the antiferromagnetism does not appear magnetic to the outside, the current signal reading of the multistate storage based on antiferromagnetism mainly depends on Anisotropic magnetoresistance, which is a weak signal for practical applications

The multi-state storage based on ferromagnetic materials uses the characteristic that changes in ferromagnetic domains will cause resistance changes to realize multi-state storage. Since the external magnetic field will affect the movement of ferromagnetic domains, such multi-state storage is unstable.

In addition, the existing methods of using spin current to drive magnetization reversal or magnetic domain movement require an auxiliary magnetic field to break the symmetry in order to realize the magnetic moment reversal under current drive, which is not conducive to the practical application of this effect.

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