Information transport in field-coupled nanomagnetic logic devices

Abstract

The information transport in field-coupled nanomagnetic logic (NML) systems is demonstrated by investigating signal propagation in a circular chain of magnets. Design criteria for the magnet layout, signal injection timing, and the required clocking field are presented. The strong interaction between the magnets is estimated by simulations and verified by hysteresis curve measurements. Signal transmission in the magnetic wire is confirmed by magnetic force microscopy measurements, especially the propagation of a metastable pair of magnets with parallel magnetization. For the first time, a field-coupled magnetic logic device is successfully operated for hundreds of clocking cycles. Extensive studies verify the reliability and robustness of information transport in field-coupled NML systems from perpendicular magnetic media.

Generalized analysis of thermally activated domain-wall motion in Co/Pt multilayers

“…For potential device applications [10][11][12][13], it is important to investigate DW dynamics in patterned strips of ferromagnetic thin films, especially materials with perpendicular magnetic anisotropy (PMA) that have shown low critical current densities and high maximum velocities for DW motion [15-22, 39, 43-45]. DWs in these out-of-plane magnetized thin films are narrow (∼1-10 nm wide) and susceptible to pinning by nanoscale defects at sufficiently low driving fields or current densities [1-8, 23-30, 33-37, 37-43].…”

“…The dynamics of magnetic domain walls (DWs) driven by magnetic field [1][2][3][4][5][6][7][8][9][10][11] or electric current is often dictated by interactions with defects.…”

1-Bit Full Adder in Perpendicular Nanomagnetic Logic using a Novel 5-Input Majority Gate

“…Similarly, M 2 will be ordered antiparallel to M z . The stepwise antiparallel ordering enables directed signal flow in a chain of magnets and constitutes the basis for logic operations in pNML circuitry [7,8].…”

“…It benefits from flexible geometries and shape independent anisotropy, which is tuned by focused ion beam (FIB) irradiation [5]. Therefore, so-called artificial nucleation centers (ANCs) are fabricated by partial FIB irradiation at user-defined positions and provide directed signal flow in chains [6][7][8] and gates [9] of field-coupled nanomagnets. Fig.…”

A robust soliton ratchet using combined antiferromagnetic and ferromagnetic interlayer couplings

“…This leads to the idea of creating a ratchet which allows only unidirectional propagation. 1,14,15 We have previously demonstrated a vertical ratchet scheme which uses entirely antiferromagnetic coupling between perpendicularly magnetized layers, using alternating layer thickness and interlayer coupling strengths. 1,16 In this paper, we demonstrate that a repeated sequence of antiferromagneticantiferromagnetic-ferromagnetic (AF-AF-F) coupled magnetic layers creates a synchronous vertical soliton ratchet whilst using layers of the same material and thickness.…”