Search

Your search keyword '"Qiu, Lei"' showing total 2,393 results
Start Over Author "Qiu, Lei"
2,393 results on '"Qiu, Lei"'

22. Wideband metasurface-loaded rectenna for azimuth-insensitive electromagnetic energy absorption using characteristic mode analysis.

Author

Deng, Lianwen, He, Zhe-Jia, Huang, Shengxiang, Qiu, Lei-Lei, and Zhu, Lei

Subjects
ELECTROMAGNETIC waves, WIRELESS power transmission, ENERGY consumption, ENERGY harvesting, ANTENNAS (Electronics)
Abstract

In this paper, a wideband metasurface-loaded (MTS-L) rectenna system is proposed to capture electromagnetic (EM) energy at arbitrary azimuth angles. The radiation patterns of different modes in the original MTS configuration are analyzed using the characteristic mode theory, and potential modes with omnidirectional radiation are screened out. By the arrangement of patches, the roundness performance of the radiation pattern can be ameliorated, and the omnidirectional characteristic is obtained over a wide frequency band. Subsequently, the surface current density of the selected mode is carefully and artificially designed to facilitate probe excitation as well as refrain from introducing complex power-combining networks. A wideband rectifier circuit is designed as the load of the proposed antenna. Eventually, measured results show that it operates from 4.6 to 9.6 GHz with a fractional bandwidth of 70.4%, and the peak system efficiency is 52.2%. The proposed system demonstrates excellent potential for wireless power transmission and EM energy harvesting in indoor environments. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

32. Geochronologic Constraints on the Rubidium Deposit of Guiren Peak, Guangdong, China

Author

Zhou, Su, Qiu, Ruizhao, Xie, Bingjing, Qiu, Lei, Liu, Cui, Lin, Dan, Pisello, Anna Laura, Editorial Board Member, Hawkes, Dean, Editorial Board Member, Bougdah, Hocine, Editorial Board Member, Rosso, Federica, Editorial Board Member, Abdalla, Hassan, Editorial Board Member, Boemi, Sofia-Natalia, Editorial Board Member, Mohareb, Nabil, Editorial Board Member, Mesbah Elkaffas, Saleh, Editorial Board Member, Bozonnet, Emmanuel, Editorial Board Member, Pignatta, Gloria, Editorial Board Member, Mahgoub, Yasser, Editorial Board Member, De Bonis, Luciano, Editorial Board Member, Kostopoulou, Stella, Editorial Board Member, Pradhan, Biswajeet, Editorial Board Member, Abdul Mannan, Md., Editorial Board Member, Alalouch, Chaham, Editorial Board Member, Gawad, Iman O., Editorial Board Member, Nayyar, Anand, Editorial Board Member, Amer, Mourad, Series Editor, Çiner, Attila, editor, Banerjee, Santanu, editor, Lucci, Federico, editor, Radwan, Ahmed E., editor, Shah, Afroz Ahmad, editor, Doronzo, Domenico M., editor, Hamimi, Zakaria, editor, and Bauer, Wilfried, editor

Published
2023
Full Text
View/download PDF

41. Dynamics of ferromagnetic bimerons driven by spin currents and magnetic fields

Author

Shen, Laichuan, Li, Xiaoguang, Xia, Jing, Qiu, Lei, Zhang, Xichao, Tretiakov, Oleg A., Ezawa, Motohiko, and Zhou, Yan

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Magnetic bimeron composed of two merons is a topological counterpart of magnetic skyrmion in in-plane magnets, which can be used as the nonvolatile information carrier in spintronic devices. Here we analytically and numerically study the dynamics of ferromagnetic bimerons driven by spin currents and magnetic fields. Numerical simulations demonstrate that two bimerons with opposite signs of topological numbers can be created simultaneously in a ferromagnetic thin film via current-induced spin torques. The current-induced spin torques can also drive the bimeron and its speed is analytically derived, which agrees with the numerical results. Since the bimerons with opposite topological numbers can coexist and have opposite drift directions, two-lane racetracks can be built in order to accurately encode the data bits. In addition, the dynamics of bimerons induced by magnetic field gradients and alternating magnetic fields are investigated. It is found that the bimeron driven by alternating magnetic fields can propagate along a certain direction. Moreover, combining a suitable magnetic field gradient, the Magnus-force-induced transverse motion can be completely suppressed, which implies that there is no skyrmion Hall effect. Our results are useful for understanding of the bimeron dynamics and may provide guidelines for building future bimeron-based spintronic devices., Comment: 8 pages, 8 figures

Published
2020
Full Text
View/download PDF

43. Antiferromagnetic Skyrmion-Based Logic Gates Controlled by Electric Currents and Fields

Author

Liang, Xue, Xia, Jing, Zhang, Xichao, Ezawa, Motohiko, Tretiakov, Oleg A., Liu, Xiaoxi, Qiu, Lei, Zhao, Guoping, and Zhou, Yan

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics
Abstract

Antiferromagnets are promising materials for future spintronic applications due to their unique properties including zero stray fields, robustness versus external magnetic fields and ultrafast dynamics, which have attracted extensive interest in recent years. In this work, we investigate the dynamics of isolated skyrmions in an antiferromagnetic nanotrack with a voltage-gated region. It is found that the skyrmion can be jointly controlled by the driving current and the voltage-controlled magnetic anisotropy gradient. We further propose a design of logic computing gates based on the manipulation of antiferromagnetic skyrmions, which is numerically realized combining several interactions and phenomena, including the spin Hall effect, voltage-controlled magnetic anisotropy effect, skyrmion-skyrmion interaction, and skyrmion-edge interaction. The proposed logic gates can perform the basic Boolean operations of the logic AND, OR, NOT, NAND and NOR gates. Our results may have a great impact on fundamental physics, and be useful for designing future non-volatile logic computing devices with ultra-low energy consumption and ultra-high storage density., Comment: 23 pages, 5 figures

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results