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- Chumak, A. V., et al.
(författare)
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Advances in Magnetics Roadmap on Spin-Wave Computing
- 2022
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Ingår i: IEEE Transactions on Magnetics. - 0018-9464. ; 58:6
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Tidskriftsartikel (refereegranskat)abstract
- Magnonics addresses the physical properties of spin waves and utilizes them for data processing. Scalability down to atomic dimensions, operation in the GHz-to-THz frequency range, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS are just a few of many advantages offered by magnons. Although magnonics is still primarily positioned in the academic domain, the scientific and technological challenges of the field are being extensively investigated, and many proof-of-concept prototypes have already been realized in laboratories. This roadmap is a product of the collective work of many authors that covers versatile spin-wave computing approaches, conceptual building blocks, and underlying physical phenomena. In particular, the roadmap discusses the computation operations with Boolean digital data, unconventional approaches like neuromorphic computing, and the progress towards magnon-based quantum computing. The article is organized as a collection of sub-sections grouped into seven large thematic sections. Each sub-section is prepared by one or a group of authors and concludes with a brief description of current challenges and the outlook of further development for each research direction. Author
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| 2. |
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| 3. |
- Artemchuk, P. Y., et al.
(författare)
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Terahertz frequency spectrum analysis with a nanoscale antiferromagnetic tunnel junction
- 2020
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 127:6
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Tidskriftsartikel (refereegranskat)abstract
- A method to perform spectrum analysis on low power signals between 0.1 and 10 THz is proposed. It utilizes a nanoscale antiferromagnetic tunnel junction (ATJ) that produces an oscillating tunneling anisotropic magnetoresistance, whose frequency is dependent on the magnitude of an evanescent spin current. It is first shown that the ATJ oscillation frequency can be tuned linearly with time. Then, it is shown that the ATJ output is highly dependent on matching conditions that are highly dependent on the dimensions of the dielectric tunneling barrier. Spectrum analysis can be performed by using an appropriately designed ATJ, whose frequency is driven to increase linearly with time, a low pass filter, and a matched filter. This method of THz spectrum analysis, if realized in the experiment, will allow miniaturized electronics to rapidly analyze low power signals with a simple algorithm. It is also found by simulation and analytical theories that for an ATJ with a 0.09 mu m(2) footprint, spectrum analysis can be performed over a 0:25 THz bandwidth in just 25 ns on signals that are at the Johnson-Nyquist thermal noise floor. Published under license by AIP Publishing.
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| 4. |
- Zahedinejad, Mohammad, 1986, et al.
(författare)
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Memristive control of mutual spin Hall nano-oscillator synchronization for neuromorphic computing
- 2022
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Ingår i: Nature Materials. - : Springer Nature. - 1476-1122 .- 1476-4660. ; 21:1, s. 81-87
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Tidskriftsartikel (refereegranskat)abstract
- Synchronization of large spin Hall nano-oscillator (SHNO) arrays is an appealing approach toward ultrafast non-conventional computing. However, interfacing to the array, tuning its individual oscillators and providing built-in memory units remain substantial challenges. Here, we address these challenges using memristive gating of W/CoFeB/MgO/AlOx-based SHNOs. In its high resistance state, the memristor modulates the perpendicular magnetic anisotropy at the CoFeB/MgO interface by the applied electric field. In its low resistance state the memristor adds or subtracts current to the SHNO drive. Both electric field and current control affect the SHNO auto-oscillation mode and frequency, allowing us to reversibly turn on/off mutual synchronization in chains of four SHNOs. We also demonstrate that two individually controlled memristors can be used to tune a four-SHNO chain into differently synchronized states. Memristor gating is therefore an efficient approach to input, tune and store the state of SHNO arrays for non-conventional computing models.
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| 5. |
- Aleman, A., et al.
(författare)
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Phase and frequency-resolved microscopy of operating spin Hall nano-oscillator arrays
- 2024
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Ingår i: NANOSCALE HORIZONS. - 2055-6756 .- 2055-6764.
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Tidskriftsartikel (refereegranskat)abstract
- Coherent optical detection is a powerful technique for characterizing a wide range of physical excitations. Here, we use two optical approaches (fundamental and parametric pumping) to microscopically characterize the high-frequency auto-oscillations of single and multiple nano-constriction spin Hall nano-oscillators (SHNOs). To validate the technique and demonstrate its robustness, we study SHNOs made from two different material stacks, NiFe/Pt and W/CoFeB/MgO, and investigate the influence of both the RF injection power and the laser power on the measurements, comparing the optical results to conventional electrical measurements. To demonstrate the key features of direct, non-invasive, submicron, spatial, and phase-resolved characterization of the SHNO magnetodynamics, we map out the auto-oscillation magnitude and phase of two phase-binarized SHNOs used in Ising machines. This proof-of-concept platform establishes a strong foundation for further extensions, contributing to the ongoing development of crucial characterization techniques for emerging computing technologies based on spintronics devices. An efficient platform to perform phase imaging and individual nano-addressing for application in novel SHNO-based computing devices.
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| 6. |
- Cherepov, Sergiy, et al.
(författare)
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Core-Core Dynamics in Spin Vortex Pairs
- 2012
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 109:9, s. 097204-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate nanopillars in which two thin ferromagnetic particles are separated by a nanometer thin nonmagnetic spacer and can be set into stable spin vortex-pair configurations. We find that the previously unexplored limit of strong vortex core-core coupling can dominate the spin dynamics in the system. We observe experimentally and explain analytically and numerically how the 0.2 GHz gyrational resonance modes of the individual vortices are transformed into a 2 GHz collective rotational resonance mode in the configurations where the two cores form a bound pair.
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| 7. |
- Sulymenko, O. R., et al.
(författare)
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Terahertz-Frequency Spin Hall Auto-oscillator Based on a Canted Antiferromagnet
- 2017
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Ingår i: Physical Review Applied. - 2331-7019. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- We propose a design of a terahertz-frequency signal generator based on a layered structure consisting of a current-driven platinum (Pt) layer and a layer of an antiferromagnet (AFM) with easy-plane anisotropy, where the magnetization vectors of the AFM sublattices are canted inside the easy plane by the Dzyaloshinskii-Moriya interaction (DMI). The dc electric current flowing in the Pt layer creates due to the spin Hall effect, a perpendicular spin current that, being injected in the AFM layer, tilts the DMI-canted AFM sublattices out of the easy plane, thus exposing them to the action of a strong internal exchange magnetic field of the AFM. The sublattice magnetizations, along with the small net magnetization vector m(DMI) of the canted AFM, start to rotate about the hard anisotropy axis of the AFM with the terahertz frequency proportional to the injected spin current and the AFM exchange field. The rotation of the small net magnetization mDMI results in the terahertz-frequency dipolar radiation that can be directly received by an adjacent (e.g., dielectric) resonator. We demonstrate theoretically that the radiation frequencies in the range f = 0.05-2 THz are possible at the experimentally reachable magnitudes of the driving current density, and we evaluate the power of the signal radiated into different types of resonators. This power increases with the increase of frequency f, and it can exceed 1 mu W at f similar to 0.5 THz for a typical dielectric resonator of the electric permittivity epsilon similar to 10 and a quality factor Q similar to 750.
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