Experimental prototype of a spin-wave majority gate

Abstract

Featuring low heat dissipation, devices based on spin-wave logic gates promise to comply with increasing future requirements in information processing. In this work, we present the experimental realization of a majority gate based on the interference of spin waves in an Yttrium-Iron-Garnet-based waveguiding structure. This logic device features a three-input combiner with the logic information encoded in the phase of the spin waves. We show that the phase of the output signal represents the majority of the phase of the input signals. A switching time of about 10 ns in the prototype device provides evidence for the ability of sub-nanosecond data processing in future down-scaled devices.The scaling of conventional CMOS-based nanoelectronics is expected to become increasingly intrinsically limited in the next decade. Therefore, novel beyond-CMOS devices are being actively developed as a complement to expand functionally in future nanoelectronic technology nodes 1 . In particular, the field of magnonics 2-7 (see also reviews 8-12) which utilizes the fundamental excitations of a magnetic system -spin waves 13 and their quanta -magnons 14 as data carriers, provides promising approaches to overcome crucial limitations of CMOS since they may provide ultralow power operation as well as nonvolatility 9,12,15 . Magnonic devices are especially amenable to building majority gates 7,16-19 with excellent scaling potential leading to an improved circuit efficiency. Hence, majority gates can be considered to be key devices in a novel approach to circuit design with strongly improved area and power scaling behavior 20 .Spin waves cover characteristic frequencies in the GHz regime and their wavelength can easily be reduced down to the nanometer range 12,21 . Furthermore, their dispersion relation is highly versatile depending on material parameters as well as magnetization and field configuration 8 making them usable in a wide range of devices [2][3][4][5][6][7]10,[22][23][24][25] . In this context, majority gates are of special interest since a simple spin-wave combiner substitutes several tens of transistors, and three majority gates suffice for creating a full-adder 26 . Multi-frequency operation allows for parallel data processing 27 .In this work, we present the experimental realization and investigation of a prototype of a spin-wave majority gate, whose functionality and performance on the microscopic scale have been investigated in numerical simulations 7,17 . The investigated majority gate has three

Magnonic crystals for data processing

“…Furthermore, this device can perform not only majority operations but also AND and OR operations if one of its inputs is used as a control input [237,239]. Recently, an experimental prototype of the three-input majority gate was realized and characterized [243]. It was proven that, in accordance with predictions from numerical simulations, the phase of the output signal represents the majority of the phase of the input signals.…”

“…• Two different designs of a micro-scaled majority gate for the processing of digital information were proposed and studied using numerical simulations [239,240] and experimentally [243]. Their functionality was proven.…”

“…Such an approach allows the trivial embedding of a NOT logic element in magnonic circuits by changing the position of the read-out device by a distance equal to half the wavelength. Moreover, it opens up access to the realization of a majority logic gate in the form of a multi-input spinwave combiner [109,191,[238][239][240][241][242][243]. The spin-wave majority gate consists of three input waveguides where spin waves are excited, a spin-wave combiner which merges the different input waveguides, and an output waveguide where a spin wave propagates with the same phase as the majority of the input waves.…”

Static and Dynamic Magnetic Properties of Single‐Crystalline Yttrium Iron Garnet Films Epitaxially Grown on Three Garnet Substrates

“…Yttrium iron garnet (YIG) is extensively used for SW devices [11][12][13] because of its low intrinsic Gilbert damping, [14][15][16][17][18][19] but other materials with low Gilbert damping have been proposed, including Permalloy [20,21] and Heusler alloys. Yttrium iron garnet (YIG) is extensively used for SW devices [11][12][13] because of its low intrinsic Gilbert damping, [14][15][16][17][18][19] but other materials with low Gilbert damping have been proposed, including Permalloy [20,21] and Heusler alloys.…”

Characterization of spin-transfer-torque effect induced magnetization dynamics driven by short current pulses

“…In this field, currents of magnons, the quanta of spin-waves, are used to transport and process information. Recently, a set of prototype devices has been realized such as, e.g., the magnonic majority gate 2,3 , in which the logic state of the output signal is determined by the majority of the input states. Other works on magnon based devices such as the magnon transistor 4 , the spin-wave multiplexer 5 , domain walls as spinwave nanochannels 6 , graded-index magnonics 7 or a signal splitter based on caustic-like spin-wave beams 8 pave the way towards a controlled spin-wave transfer in magnonic networks.…”