85 research outputs found
Spin orbit torque induced asymmetric depinning of chiral Néel domain wall in Co/Ni heterostructures
In this letter, we report on distinct depinning of a chiral Néel domain wall (DW) driven by spin-orbit torque (SOT) in Co/Ni nanowires with symmetric potential barriers. In these structures, DW propagation was shown to be in the opposite direction to the electron flow as evidenced from current assisted DW depinning measurements. A transition from field dominated DW depinning to SOT dominated DW depinning was observed as the bias current was increased. For SOT dominated DW depinning, the Up-Down DW exhibits a larger depinning field as compared to the Down-Up DW. This is attributed to the interplay between the SOT and Dzyaloshinskii-Moriya interaction in the structure
Asymmetrical domain wall propagation in bifurcated PMA wire structure due to the Dzyaloshinskii-Moriya interaction
Controlling domain wall (DW) motion in complex magnetic network structures is of paramount significance for the development of spin-based devices. Here, we report on the dynamics of a propagating DW in a bifurcated ferromagnetic wire with perpendicular magnetic anisotropy (PMA). The Dzyaloshinskii-Moriya interaction (DMI) in the wire structure induces a tilt angle to the injected DW, which leads to a quasi-selective propagation through the network branch. The DW tilting causes a field interval between DWs to arrive at Hall bars in the individual branches. Micromagnetic results further show that by tailoring the strength of the DMI, the control of DW dynamics in the PMA complex network structures can be achieved
Geometrically Tailored Skyrmions at Zero Magnetic Field in Multilayered Nanostructures
Magnetic skyrmions are chiral spin structures recently observed at room temperature in multilayer films. Their topological stability will enable high scalability in confined geometries—a sought-after attribute for device applications. Despite numerous theoretical studies examining sub-100-nm Néel skyrmions in nanostructures, in practice their ambient stability and evolution with confinement and their magnetic parameters remain to be established. Here we present the zero-field stabilization of sub-100-nm room-temperature Néel-textured skyrmions confined in Ir/Fe(x)/Co(y)/Pt nanodots over a wide range of magnetic and geometric parameters. The zero-field skyrmion size, here as small as approximately 50 nm, can be tailored by a factor of 4 with variation of dot size and magnetic interactions. Crucially, skyrmions with differing thermodynamic stability exhibit an unexpected dichotomy in confinement phenomenologies. These results establish skyrmion phenomenology in multilayer nanostructures, and prompt the synergistic use of magnetic and geometric parameters to achieve desired properties in devices
Transverse Domain Wall Profile for Spin Logic Applications
Domain wall (DW) based logic and memory devices require precise control and manipulation of DW in nanowire conduits. The topological defects of Transverse DWs (TDW) are of paramount importance as regards to the deterministic pinning and movement of DW within complex networks of conduits. In-situ control of the DW topological defects in nanowire conduits may pave the way for novel DW logic applications. In this work, we present a geometrical modulation along a nanowire conduit, which allows for the topological rectification/inversion of TDW in nanowires. This is achieved by exploiting the controlled relaxation of the TDW within an angled rectangle. Direct evidence of the logical operation is obtained via magnetic force microscopy measurement
On the growth mechanism of nickel and cobalt nanowires and comparison of their magnetic properties
The State of Qualitative Research Methods in Tourism and Hospitality: Research Design Issues and The Way Forward
Within the field of tourism and hospitality, qualitative research as a method gained recognition only in the early 1990s. Qualitative research in tourism and hospitality research has primarily taken inspiration from the anthropology, sociology, and geography disciplines. Prior to the 1990, the field was largely dominated by research based on positivistic philosophies. Since then, researchers have started to question the fundamental nature of quantitative research, as it couldn't address the questions of meanings and understandings. Qualitative research was, therefore, considered as an alternative method offering richer interpretations and understanding of lived realities. While there has been a surge in qualitative methods over the years, quantification is still a dominant paradigm in much of the tourism and hospitality scholarship. Qualitative research is still portrayed as less methodologically robust, lacking rigor and credibility. Hence various attempts have been made to overcome the weaknesses. To understand how qualitative studies can be further developed to generate robust theoretical advancement, it is important to first understand the historical development of qualitative research within the field. We also provide insight on some of the most common types of qualitative inquiries used in tourism and hospitality research as well as their inherent challenges.No Full Tex
Giant damping-like spin orbit torque in perpendicular magne-tized double Pt/Co stack structure
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