Chiral Magnonics: Reprogrammable Nanoscale Spin Wave Networks Based on Chiral Domain Walls.

Haiming Yu,Junfeng Hu,Jilei Chen

doi:10.1016/j.isci.2020.101153

Abstract

SummarySpin waves offer promising perspectives as information carriers for future computational architectures beyond conventional complementary metal-oxide-semiconductor (CMOS) technology, owing to their benefits for device minimizations and low-ohmic losses. Although plenty of magnonic devices have been proposed previously, scalable nanoscale networks based on spin waves are still missing. Here, we demonstrate a reprogrammable two-dimensional spin wave network by combining the chiral exchange spin waves and chiral domain walls. The spin-wave network can be extended to two dimensions and offers unprecedented control of exchange spin waves. Each cell in the network can excite, transmit, and detect spin waves independently in the chiral domain wall, and spin-wave logics are also demonstrated. Our results open up perspectives for integrating spin waves into future logic and computing circuits and networks.

Highlights

As elementary spin excitations in magnetic materials, spin waves are promising candidates as information carriers for the future computational architectures (Chumak et al, 2015; Kruglyak et al, 2010; Demidov et al, 2017)
When the Dzyaloshinskii-Moriya interaction (DMI) is introduced, it will result in an asymmetric spin wave dispersion, which will lead to a non-reciprocal spin wave propagation as (Garcia-Sanchez et al, 2015): sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi u=
Owing to the dynamic dipolar coupling and the boundary condition formed by the double nanowires, only the spin waves with wave numbers k = np=a with n = 2, 4, 6. can be excited, where a is the distance between two identical nanowires

Summary

Introduction

As elementary spin excitations in magnetic materials, spin waves are promising candidates as information carriers for the future computational architectures (Chumak et al, 2015; Kruglyak et al, 2010; Demidov et al, 2017). Exchange spin waves with wavelengths around 10 nm exhibit a high group velocity of ~13.1 km/s, ten times faster than the dipolar spin waves in a thin-film magnetic insulator (Liu et al, 2018). Experimental observations of exchange spin waves via magnetic nano-arrays have opened a horizon for applying exchange spin waves in magnonic devices and circuits (Yu et al, 2016). Chiral excitation of exchange spin waves allows unidirectional spin-wave propagation (Chen et al, 2019b), which is key to the realization of magnonic logic devices and circuits. Plenty of magnonic devices have been proposed previously, such as magnonic transistors (Chumak et al, 2014), diodes (Lan et al, 2015), and directional couplers (Wang et al, 2018), scalable nanoscale magnonic networks are still missing

Methods

Results

Conclusion