Spin-wave Logic Gates Research Articles

Strain-induced multi-band spin-wave logic gate based on alligator-type magnonic crystal/PZT structure

Here, we report the results of strain-controlled spin-wave propagation regimes in a double-period multiferroic structure. It consists of an alligator-type magnonic crystal with a period of 250 μm and a piezoelectric layer, featuring a periodic counter-pin-type electrode system with a period of 125 μm. Employing microwave measurements, we acquired the transmission and dispersion of spin waves under various external electric field configurations applied to the piezoelectric layer. The formation of bandgaps in the magnon spectrum and the variation of the spin-wave transmission when altering the configurations of the external electric field are demonstrated. A finite element method reveals that the combination of the non-uniformity in the initial internal magnetic field of the magnonic crystal, which is caused by the presence of periodic alligator-type regions, together with elastic deformations, heightens the amplitude of the modulation of the internal magnetic field. Micromagnetic modeling has demonstrated that this modulation enhancement results in the variation of the spin-wave transmission at the frequency of the magnonic bandgap center of the magnonic crystal. The proposed design of the reconfigurable magnonic crystal creates a condition for the nucleation of the spin-wave bandgap, with further enhancement of the spin-wave reflection from the periodic grating induced by strain. We demonstrate the potential use of the proposed device as a multi-band NAND/NXOR spin-wave based logic gate.

Investigation of a Nonlinear XNOR Logic Gate Based on an Induced Nonlinear Phase Shift of Spin Waves

Introduction. Recent years have seen a growing interest in studying the nonlinear properties of spin waves. Nonlinear phenomena, such as envelope solitons, nonlinear frequency shifts of intense spin waves, and etc., have attracted particular attention. However, a number of important issues remain to be underexplored, including the problem of induced nonlinear phase shift of spin waves. The relevance of this problem is related to the need to develop spin-wave logic gates that could be controlled by changing the spin wave phase.Aim. To study a nonlinear XNOR logic gate whose operation is based on the induced nonlinear phase shift of a spin wave.Materials and methods. An original theory is used to simulate the frequency response of a nonlinear XNOR logic gate. The operating principle of the nonlinear XNOR logic gate is substantiated. The possibility of implementing the nonlinear XNOR logic gate in a circuit similar to a spin-wave Mach-Zehnder interferometer is experimentally demonstrated.Results. An experimental study of the induced nonlinear phase shift of operating signals incident on identical nonlinear spin-wave phase shifters located in the arms of the logic gate was carried out. It is shown that an increase in the pump signal power up to 60 mW, supplied to nonlinear phase shifters, changes the induced nonlinear phase shift of the operating signal by more than 180°. Hence, nonlinear phase shifters can be used for constructing spin-wave logic gates. In addition, the operating principle of a spin-wave logic gate was experimentally studied. It is shown that the XNOR logical function is implemented in the low-frequency part of the device’s frequency response characteristic.Conclusion. Numerical simulation of the characteristics of a nonlinear XNOR logic gate based on the Mach-Zehnder interferometer circuit was carried out. It is shown that its logical functions are implemented due to the effect of an induced nonlinear phase shift of spin waves in nonlinear phase shifters located in different arms of the logic gate.

Operation of a submicrometer waveguide cross as a spin-wave logic gate

In this experimental study, we explore the potential implementation of logic operations using the interference of propagating spin waves within a device composed of intersecting yttrium iron garnet waveguides with submicrometer width. Our investigation reveals the significant influence of finite-size effects on the performance of the microscopic devices. In particular, we observe that their efficiency depends on the wavelengths of the involved spin waves in relation to the size of the interference region and is reduced by multimode spin-wave propagation. These findings highlight crucial factors to be considered when designing magnonic nanodevices operating with short-wavelength spin waves, providing valuable insights for optimizing their performance in practical applications.

Dual function spin-wave logic gates based on electric field control magnetic anisotropy boundary

Spin waves (SWs) have been considered a promising candidate for encoding information with lower power consumption. Here, we propose dual function SW logic gates, one unit cell with two synchronized logic operation functions, based on the electric field controlling of the SW propagation in the Fe film of a Fe/BaTiO3 heterostructure by the motion of a magnetic anisotropy boundary. We show micromagnetic simulations to validate the and–or and nand–nor logic gates. Our research may find a path for simplifying integrated logic circuits using such dual function SW logic gates.

Recent advances in key elements of spin-wave logic gates

Traditional charge-based device development is approaching the limit of Moores law, thus, there is a desperate need for new information processing principles or architectures. Replacing traditional charge-based devices with non-charge-based devices for information processing shows promise. Spin waves, which are generated from the collective precession of electron spins, are thought to be an important information carrier for the transmission and processing of information in a beyond-Moore era. Spin-wave logic gates possess incomparable advantages over traditional logic devices in energy consumption, device scale, application frequency, and logical operation, among other factors. This article explains the operating principles of spin-wave logic gates based on a Mach-Zehnder interferometer structure, and then analyzes the realization theory of key spin-wave logic gate elements at a device level. Recent advances in these key elements are also reviewed systematically. Lastly, future prospects of spin-wave logic gates are discussed.

A spin-wave logic gate based on a width-modulated dynamic magnonic crystal

An electric current controlled spin-wave logic gate based on a width-modulated dynamic magnonic crystal is realized. The device utilizes a spin-wave waveguide fabricated from a single-crystal Yttrium Iron Garnet film and two conducting wires attached to the film surface. Application of electric currents to the wires provides a means for dynamic control of the effective geometry of waveguide and results in a suppression of the magnonic band gap. The performance of the magnonic crystal as an AND logic gate is demonstrated.

Realization of spin-wave logic gates

We demonstrate the functionality of spin-wave logic exclusive-not-OR and not-AND gates based on a Mach-Zehnder-type interferometer which has arms implemented as sections of ferrite film spin-wave waveguides. Logical input signals are applied to the gates by varying either the phase or the amplitude of the spin waves in the interferometer arms. This phase or amplitude variation is produced by Oersted fields of dc current pulses through conductors placed on the surface of the magnetic films.

Spin-wave logical gates

A universal approach to spin-wave logic gates is presented. The feasibility of a spin-wave based NOT gate has been demonstrated experimentally. We propose to use a Mach–Zender-type current-controlled interferometer based on spin-wave propagation in a ferromagnetic film to construct logical gates. We investigate the performance of the main element of such interferometric logical gates—the controlled phase shifter implemented as a spin-wave device.