All-electric drive magnetic logic device

In the past few decades to improve computer performance depends on the continued miniaturization of silicon-based semiconductor devices. With the size of the device gradually approaching the physical limits, significantly increasing reliability and lowering operating power consumption is becoming a barrier to further restricting the development of computers. After depletion bonus scale effect, Moore\’s Law dependence development and technological innovation device configuration of new materials. Thanks to fast response, high integration density and other technical advantages and nonvolatile, magnetic devices and magnetic material chosen from a super molar Innovation. In 2008, IBM announced a new generation of storage technology: Racetrack racetrack memory technology based on electromagnetic coupling. This technique combines the mechanical characteristics of the hard disk and flash memory, along with a large storage capacity and high storage speed. Breakthrough storage device to the logic device development has brought a new dawn and power. Magnetic logic device is a powerful successor to conventional CMOS logic devices, is also popular in recent years of scientific research. A nonvolatile memory function and logic operations having an intrinsic magnetic logic device can be realized calculated (logic-in-memory) in the memory, which may create a non-computer-Von Neumann architecture to support such things , new applications require large data and artificial intelligence operations, and mass data storage. However, the control logic of the existing magnetic interventions mostly dependent on an external magnetic field, the practical application difficult. Swiss Institute of Technology in Zurich (ETH Zürich) and the Swiss Paul Scherrer Institute (Paul Scherrer Institute) of Dr. Luozhao early , Professor Laura Heyderman [123 ] and Professor Pietro Gambardella and our research team has recently made significant progress in the all-electric drive magnetic logic device aspects. This study is based on the technology Racetrack are, by improving the structure of the track introduces a stable and controllable magnetic domain structure, and the use of a chiral coupling between the adjacent magnetic domains, enables logic device functionality and all-electric drive. The research results (Current-driven magnetic domain-wall logic) in 2020On March 12, published in \”Nature\” (Nature) journal (Nature, 2020. doi.org/10.5281/zenodo.3557288.) The study demonstrated the all-electric drive magnetic logic device consists of Pt / Co / AlOx three-layer structure the nanowires. Process and device structure shown in Figure 1a. Plated with Si / SiNx substrate Pt / Co / Al three-layer film, by photolithography and ion beam etching nanowire structure is formed, and finally the device is formed by local oxidation of the Al layer. The initial magnetization state of the device shown in FIG. 1b, Co layer exhibits three kinds magnetization direction. Two magnetic domains oriented outer surface opposite to a surface to be spaced apart from the magnetic domains (the outer surface and the inner surface of the magnetic domains corresponding area below the AlOx and Al), and the orientation of adjacent magnetic domains as a particular chiral features (Figure 1b for left-handed). Such chiral characterized by several factors derived from the equilibration 🙁 a) Pt-Co at the interface of the spin – orbit coupling effect of Co-O and Co-AlOx interface at the direction of magnetization of the Co layer is biased in the vertical direction (perpendicular magnetic anisotropy); (ii) Dzyaloshinskii-Moriya interaction Pt-Co at the interface (DMI) acting to force the adjacent magnetic domains oriented perpendicular to each other and form a chiral; (c) a perpendicular magnetic Co-Al interface relatively weak anisotropy, to create the conditions for the formation of in-plane orientation. Flip This stable chiral coupling means unilateral external surface orientation will inevitably lead to the inner surface of the other side and flipped the outer surface orientation, which enables logic NAND gate function. Figure 1c illustrates the principle and process of the device implementing logical functions. Left partially oriented downward magnetic domains are formed after reversing the magnetic domain wall in the region of the border are not inverted. When energized, the flow of electrons driven by the spin Hall effect occurs in the spin current deflecting the Pt layer is formed in the vertical direction. Injecting spin-spin flow generated at the domain wall – track moments (the HSOT FIG. 1c), forcing the magnetization direction of the domain wall from rotating to drive the domain wall to move forward until all the magnetic domains on the track are the overturn. FIG. 1d, the use of magneto – optical Kerr effect microscope (of MOKE) real-time observations confirmed this process. In FIG OF NAND configuration 1b shown as a basic module is further constructed with a non-reconfigurable (NAND) / NOR (NOR) logic gates. 2a, the logic gate of the two input terminals (a and b), a bias terminal and an output terminal configured. An input terminal a, b and bias end constitutes a majority decision logic gate. By controlling the initial state of the bias terminal, the switching can be achieved with non-/ NOR. Under the OF NAND and NOR architecture of the four devices were produced, corresponding to four input states, and using high-resolution magnetic force microscope (MFM) demonstrate the effectiveness of the device. NAND and NOR gate magnetic achieved is important, because they are core logic operation, any Boolean logic may be implemented by a single or multiple / or in combination with non-gate. As shown in FIG. 3B and C, are directly connected by a plurality of NAND gates, respectively, to achieve the full adder and half adder function. The authors also further functional magnetic logic devices have been expanded. Using a Y-shaped structure as shown in Figure 3a, the electrical signal may be used to select and assign achieve magnetic input signal. Through the above experiments, the authors demonstrate a novel magnetic logic device design, and demonstrates the logic functionality of the device and type of all-electric drive. Although the experiment in order to simplify initialization signal reading and design, the device still needs the external magnetic field and the magnetic signal detecting device, respectively, but as the author in the paper pointed out, these external aids can be implanted through a mature technology The magnetic tunnel junction (magnetic tunnel junctions) instead. The all-electric drive with its magnetic logic device highly integrated, ultra-fast response speed, low power consumption and non-volatile, electronic logic devices is expected to replace in the near future, and open a new chapter with the magnetic memory of computer development. MFM tested in this work is performed on a Bruker AFM Dimension ICON system. PS: thanks to the early lead author Dr. Luo Zhao errata for this article! Papers link: https: //www.nature.com/articles/s41586-020-2061-y