A reconfigurable waveguide for energy-efficient transmission and local manipulation of information in a nanomagnetic device

Abstract

Spin-wave-based devices promise to usher in an era of low-power computing where information is carried by the precession of the electrons' spin instead of dissipative translation of their charge. This potential is, however, undermined by the need for a bias magnetic field, which must remain powered on to maintain an anisotropic device characteristic. Here, we propose a reconfigurable waveguide design that can transmit and locally manipulate spin waves without the need for any external bias field once initialized. We experimentally demonstrate the transmission of spin waves in straight as well as curved waveguides without a bias field, which has been elusive so far. Furthermore, we experimentally show a binary gating of the spin-wave signal by controlled switching of the magnetization, locally, in the waveguide. The results have potential implications in high-density integration and energy-efficient operation of nanomagnetic devices at room temperature.

Understanding magnetotransport signatures in networks of connected permalloy nanowires

“…Local interactions result in so-called "ice rules" that 33 govern the number of moments pointing into and out of each vertex to minimize the 34 local magnetostatic energy. Artificial spin ice structures have proven to be exemplary 35 systems in which to study frustration [5,6] and have been noted for their technological 36 potential as both a reconfigurable metamaterial and as a memory storage medium [7,8,37 9, 10,11,12]. Connected artificial spin ice in particular has been studied extensively in 38 the last decade [13,14,15,16,17,18,19,20,21,22,23,24,25].…”

Isotropic transmission of magnon spin information without a magnetic field

“…Observation of similar spectra for three channels, which are at different angles, refers to the isotropic nature of the propagating modes. In contrast, note here that the spin-wave spectra vary with varying the curvature of the microconduit for DE spin waves typically used so far ( 18 , 32 ). …”

“…Usually, DE spin waves are chosen in demonstrations that use lithographically fabricated microconduits due to their large group velocity—resulting in large propagation length, efficient coupling with inductive excitation elements, and suitability for spin-orbit torque-based control ( 17 ). However, these devices are inefficient for transmitting spin waves in a curved microconduit ( 7 , 18 ). On the other hand, FV spin waves support spatially isotropic propagation of spin waves, which could enable transmission of information in any arbitrary directions—advantageous for circuit implementation.…”

Spin-wave propagation steered by electric field modulated exchange interaction

“…Magnonics is deemed as the most promising candidate for information transmission and processing1234 where information is carried by the collective precession of the electrons’ spin (namely spin waves) instead of dissipative translation of their charge. Magnons (quanta of spin waves) allow for the transport and processing of spin information without the movement of any real particles, thus, it is free of Joule heat dissipation56.…”

“…Delicate as the designs are, there are some drawbacks and problems inherent to magnetic fields. First of all, generating local Oersted field through an underlying current-carrying stripe would complicate the device structure14 especially in curved waveguides, and the current-carrying wire will continuously draw power from the system which could inhibit the benefits of magnonic devices1. In addition, a spatial inhomogeneity in local fields and stray field from neighbouring branch will give rise to poor reliability and high bit error rates.…”