Direct imaging of an inhomogeneous electric current distribution using the trajectory of magnetic half-skyrmions
Type
ArticleAuthors
Zhang, Senfu
Zhang, Xichao
Zhang, Junwei
Ganguly, Arnab
Xia, Jing
Wen, Yan
Zhang, Qiang
Yu, Guoqiang
Hou, Zhipeng
Wang, Wenhong
Peng, Yong
Xiao, Gang
Manchon, Aurelien
Kosel, Jürgen
Zhou, Yan
Zhang, Xixiang
KAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionElectrical Engineering Program
Imaging and Characterization Core Lab
Material Science and Engineering
Material Science and Engineering Program
Nanofabrication Core Lab
Physical Science and Engineering (PSE) Division
Sensing, Magnetism and Microsystems Lab
Spintronics Theory Group
Thin Films & Characterization
KAUST Grant Number
CRF-2015-SENSORS-2708OSR-2016-CRG5-2977
OSR-2017-CRG6-3427
Date
2020-02-07Online Publication Date
2020-02-07Print Publication Date
2020-02Submitted Date
2019-05-28Permanent link to this record
http://hdl.handle.net/10754/661482Metadata
Show full item recordAbstract
The direct imaging of current density vector distributions in thin films has remained a daring challenge. Here, we report that an inhomogeneous current distribution can be mapped directly by the trajectories of magnetic half-skyrmions driven by an electrical current in Pt/Co/Ta trilayer, using polar magneto-optical Kerr microscopy. The half-skyrmion carries a topological charge of 0.5 due to the presence of Dzyaloshinskii-Moriya interaction, which leads to the half-skyrmion Hall effect. The Hall angle of half-skyrmions is independent of current density and can be reduced to as small as 4° by tuning the thickness of the Co layer. The Hall angle is so small that the elongation path of half-skyrmion approximately delineates the invisible current flow as demonstrated in both a continuous film and a curved track. Our work provides a practical technique to directly map inhomogeneous current distribution even in complex geometries for both fundamental research and industrial applications.Citation
Zhang, S., Zhang, X., Zhang, J., Ganguly, A., Xia, J., Wen, Y., … Zhang, X.-X. (2020). Direct imaging of an inhomogeneous electric current distribution using the trajectory of magnetic half-skyrmions. Science Advances, 6(6), eaay1876. doi:10.1126/sciadv.aay1876Sponsors
This publication is based on research supported by the King Abdullah University of Science and Technology (KAUST), Office of Sponsored Research (OSR), under award nos. OSR-2016-CRG5-2977, OSR-2017-CRG6-3427, and CRF-2015-SENSORS-2708. X.Z. acknowledges the support by the Presidential Postdoctoral Fellowship of The Chinese University of Hong Kong, Shenzhen (CUHKSZ). Y.Z. acknowledges the support by the President’s Fund of CUHKSZ, Longgang Key Laboratory of Applied Spintronics, National Natural Science Foundation of China (grant no. 11574137), and Shenzhen Fundamental Research Fund (grant nos. JCYJ20160331164412545 and JCYJ20170410171958839). W.W. acknowledge financial support by the National Key R&D Program of China (no. 2017YFA0303202). Author contributions: S.Z. and X.-X.Z. conceived and coordinated the project and analyzed the data. X.Z., J.X., and Y.Z. developed the theoretical model. Y.W. and S.Z. fabricated the samples, and S.Z. performed the MOKE measurements. S.Z., X.Z., and X.-X.Z. wrote the manuscript. The study was supervised by X.-X.Z. All authors contributed to the discussion and preparation of the manuscript. Competing interests: The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.Journal
Science AdvancesAdditional Links
https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aay1876https://advances.sciencemag.org/content/advances/6/6/eaay1876.full.pdf
Scopus Count
Collections
Nanofabrication Core Lab; Articles; Imaging and Characterization Core Lab; Physical Science and Engineering (PSE) Division; Spintronics Theory Group; Electrical Engineering Program; Material Science and Engineering Program; Sensing, Magnetism and Microsystems Lab; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionRelated items
Showing items related by title, author, creator and subject.
-
Spin-Decoupled Multifunctional Metasurface for Asymmetric Polarization Generation(ACS Photonics, American Chemical Society (ACS), 2019-10-28) [Article]Integrating multiple functionalities into a single device is a striking field in metasurfaces. One promising aspect is polarization-dependent meta-devices enabled by simultaneous phase control over orthogonally polarized waves. Among these, Pancharatnam-Berry (PB) metasurfaces have drawn enormous interest owing to their natural and robust phase control ability over different circularly polarized waves. However, the phase responses are locked to be opposite with each other, resulting in interrelated functionalities under the circularly polarized incidence. Here, a generic designing method based on transmission-type dielectric metasurfaces is proposed in the terahertz regime, which breaks this relation by further incorporating dynamic phase with geometric phase, namely, spin-decoupled phase control method. We demonstrate this method by designing and characterizing an efficient multifunctional meta-grating, which splits different circularly polarized waves to asymmetric angles under normal incidences. More importantly, we promote this method by designing several multiplexed meta-gratings for applications of asymmetric polarization generation, which can convert arbitrary linearly polarized wave to two different linearly polarized waves with nearly equal strength and split them to asymmetric angles with a polarization-insensitive efficiency. The designing strategy proposed here shows an impressive robustness and a great flexibility for designing multifunctional metasurface-based devices and opens new avenues toward modulation of polarization states and the application of metasurfaces in beam steering and polarization multiplexing systems.
-
The Visual Object Tracking VOT2017 Challenge Results(2017 IEEE International Conference on Computer Vision Workshops (ICCVW), Institute of Electrical and Electronics Engineers (IEEE), 2018-01-22) [Conference Paper]The Visual Object Tracking challenge VOT2017 is the fifth annual tracker benchmarking activity organized by the VOT initiative. Results of 51 trackers are presented; many are state-of-the-art published at major computer vision conferences or journals in recent years. The evaluation included the standard VOT and other popular methodologies and a new 'real-time' experiment simulating a situation where a tracker processes images as if provided by a continuously running sensor. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The VOT2017 goes beyond its predecessors by (i) improving the VOT public dataset and introducing a separate VOT2017 sequestered dataset, (ii) introducing a realtime tracking experiment and (iii) releasing a redesigned toolkit that supports complex experiments. The dataset, the evaluation kit and the results are publicly available at the challenge website1.
-
Unveiling of the energy storage mechanisms of multi -modified (Nb2O5@C)/rGO nanoarrays as anode for high voltage supercapacitors with formulated ionic liquid electrolytes(Electrochimica Acta, Elsevier Ltd, 2019-04-29) [Article]A better understanding of the energy-storage mechanisms in complex pseudocapacitive nanostructures is essential to improve the performances of nanohybrid supercapacitors. In this study, highly interface modified Nb2O5 nanoarrays, attached to graphene nanosheets, were carefully designed and synthesized. The electrochemical performances were evaluated in an organic electrolyte, a formulated ionic-liquid mixture electrolyte, and a nanocomposite ionogel electrolyte, respectively. The capacitive and faradaic storage contributions were assessed qualitatively in diverse electrolytes at various temperatures. The capacitive contribution in the ionic liquid electrolyte was found to rise with increasing temperature. A molecular dynamics simulation proved that the increased diffusion coefficient of large ions was much more pronounced than that of the small Li+ ions. A carefully optimized quasi-solid-state lithium ion capacitor, fabricated using a (Nb2O5@C)/rGO nanoarchitecture as the anode and an ionic liquid gel separator, delivered an energy density of 101 Wh kg−1 and a power density of 24 kW kg−1 at 60 °C. The efficient coupling between the nanohybrids and a complex ionogel electrolyte opens a new window for the rational design of high energy-density supercapacitors.
