Two-dimensional van der Waals electrical contact to monolayer MoSi2N4
作者：
Cao, Liemao;Zhou, Guanghui;Wang, Qianqian;Ang, L. K.* ;Ang, Yee Sin*
期刊：
Applied Physics Letters ,2021年118(1):013106 ISSN：0003-6951
通讯作者：
Ang, L. K.;Ang, Yee Sin
作者机构：
[Cao, Liemao] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Wang, Qianqian; Cao, Liemao; Ang, L. K.; Ang, Yee Sin] Singapore Univ Technol & Design SUTD, Sci Math & Technol SMT, 8 Somapah Rd, Singapore 487372, Singapore.;[Zhou, Guanghui] Hunan Normal Univ, Dept Phys, Changsha 410081, Peoples R China.
通讯机构：
[Ang, LK; Ang, YS] S;Singapore Univ Technol & Design SUTD, Sci Math & Technol SMT, 8 Somapah Rd, Singapore 487372, Singapore.
摘要：
A two-dimensional (2D) MoSi2N4 monolayer is an emerging class of air-stable 2D semiconductors possessing exceptional electrical and mechanical properties. Despite intensive recent research effort devoted to uncover the material properties of MoSi2N4, the physics of electrical contacts to MoSi2N4 remains largely unexplored thus far. In this work, we study van der Waals heterostructures composed of MoSi2N4 contacted by graphene and NbS2 monolayers using first-principles density functional theory calculations. We show that the MoSi2N4/NbS2 contact exhibits an ultralow Schottky barrier height (SBH), which is beneficial for nanoelectronics applications. For the MoSi2N4/graphene contact, the SBH can be modulated via the interlayer distance or via external electric fields, thus opening up an opportunity for reconfigurable and tunable nanoelectronic devices. Our findings provide insights into the physics of 2D electrical contacts to MoSi2N4 and shall offer a critical first step toward the design of high-performance electrical contacts to MoSi2N4-based 2D nanodevices.
语种：
英文
展开
Injection of oxygen vacancies in the bulk lattice of layered cathodes
作者：
Yan, Pengfei* ;Zheng, Jianming;Tang, Zhen-Kun;Devaraj, Arun;Chen, Guoying;...
期刊：
Nature Nanotechnology ,2019年14(6):602-608 ISSN：1748-3387
通讯作者：
Yan, Pengfei;Wang, Chongmin;Liu, Li-Min
作者机构：
[Devaraj, Arun; Yan, Pengfei; Wang, Chongmin] Pacific Northwest Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA.;[Yan, Pengfei] Beijing Univ Technol, Inst Microstruct & Properties Adv Mat, Beijing Key Lab Microstruct & Properties Solids, Beijing, Peoples R China.;[Zheng, Jianming; Zhang, Ji-Guang] Pacific Northwest Natl Lab, Energy & Environm Directorate, Richland, WA 99352 USA.;[Tang, Zhen-Kun] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang, Peoples R China.;[Tang, Zhen-Kun; Liu, Li-Min] Beihang Univ, Sch Phys, Beijing, Peoples R China.
通讯机构：
[Yan, PF; Wang, CM] P;[Yan, Pengfei; Liu, Li-Min] B;Pacific Northwest Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA.;Beijing Univ Technol, Inst Microstruct & Properties Adv Mat, Beijing Key Lab Microstruct & Properties Solids, Beijing, Peoples R China.;Beihang Univ, Sch Phys, Beijing, Peoples R China.
摘要：
Surfaces, interfaces and grain boundaries are classically known to be sinks of defects generated within the bulk lattice. Here, we report an inverse case by which the defects generated at the particle surface are continuously pumped into the bulk lattice. We show that, during operation of a rechargeable battery, oxygen vacancies produced at the surfaces of lithium-rich layered cathode particles migrate towards the inside lattice. This process is associated with a high cutoff voltage at which an anionic redox process is activated. First-principle calculations reveal that triggering of this redox process leads to a sharp decrease of both the formation energy of oxygen vacancies and the migration barrier of oxidized oxide ions, therefore enabling the migration of oxygen vacancies into the bulk lattice of the cathode. This work unveils a coupled redox dynamic that needs to be taken into account when designing high-capacity layered cathode materials for high-voltage lithium-ion batteries. © 2019, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.
语种：
英文
展开
Interference-assisted kaleidoscopic meta-plexer for arbitrary spin-wavefront manipulation
作者：
Xu, He-Xiu* ;Hu, Guangwei;Li, Ying;Han, Lei;Zhao, Jianlin;...
期刊：
光：科学与应用 ,2019年8(1):3 ISSN：2095-5545
通讯作者：
Xu, He-Xiu;Qiu, Cheng-Wei;Cui, Tie Jun
作者机构：
[Han, Lei; Xu, He-Xiu; Hu, Guangwei; Qiu, Cheng-Wei; Li, Ying; Xu, HX] Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117583, Singapore.;[Xu, He-Xiu; Wang, Guang-Ming; Yuan, Fang] Air Force Engn Univ, Air & Missile Def Coll, Xian 710051, Shaanxi, Peoples R China.;[Xu, He-Xiu; Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang 421008, Peoples R China.;[Han, Lei; Zhao, Jianlin] Northwestern Polytech Univ, Sch Nat & Appl Sci, Xian 710072, Shaanxi, Peoples R China.;[Sun, Yunming] Adv Tech Dept, Key Lab Aeronaut Comp Tech, Xian 710075, Shaanxi, Peoples R China.
通讯机构：
[Xu, HX; Qiu, CW] N;[Xu, He-Xiu] A;[Xu, He-Xiu] H;[Cui, Tie Jun] S;Natl Univ Singapore, Dept Elect & Comp Engn, Singapore 117583, Singapore.
摘要：
Achieving simultaneous polarization and wavefront control, especially circular polarization with the auxiliary degree of freedom of light and spin angular momentum, is of fundamental importance in many optical applications. Interferences are typically undesirable in highly integrated photonic circuits and metasurfaces. Here, we propose an interference-assisted metasurface-multiplexer (meta-plexer) that counterintuitively exploits constructive and destructive interferences between hybrid meta-atoms and realizes independent spin-selective wavefront manipulation. Such kaleidoscopic meta-plexers are experimentally demonstrated via two types of single-layer spin-wavefront multiplexers that are composed of spatially rotated anisotropic meta-atoms. One type generates a spin-selective Bessel-beam wavefront for spin-down light and a low scattering cross-section for stealth for spin-up light. The other type demonstrates versatile control of the vortex wavefront, which is also characterized by the orbital angular momentum of light, with frequency-switchable numbers of beams under linearly polarized wave excitation. Our findings offer a distinct interference-assisted concept for realizing advanced multifunctional photonics with arbitrary and independent spin-wavefront features. A variety of applications can be readily anticipated in optical diodes, isolators, and spin-Hall meta-devices without cascading bulky optical elements. © 2019, The Author(s).
语种：
英文
展开
Recent advances in the spin Hall effect of light
作者：
Ling, Xiaohui;Zhou, Xinxing;Huang, Kun;Liu, Yachao;Qiu, Cheng-Wei* ;...
期刊：
Reports on Progress in Physics ,2017年80(6):066401 ISSN：0034-4885
通讯作者：
Qiu, Cheng-Wei
作者机构：
[Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang 421002, Peoples R China.;[Qiu, Cheng-Wei; Ling, Xiaohui] Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117576, Singapore.;[Wen, Shuangchun; Luo, Hailu; Ling, Xiaohui; Liu, Yachao] Hunan Univ, Sch Phys & Elect, Minist Educ, Lab Micro Nanooptoelect Devices, Changsha 410082, Hunan, Peoples R China.;[Zhou, Xinxing] Hunan Normal Univ, Coll Phys & Informat Sci, Synerget Innovat Ctr Quantum Effects & Applicat, Changsha 410081, Hunan, Peoples R China.;[Huang, Kun] Agcy Sci Technol & Res, Inst Mat Res & Engn, 2 Fusionopolis Way,Innovis 08-03, Singapore 138634, Singapore.
通讯机构：
[Qiu, Cheng-Wei] N;[Qiu, Cheng-Wei] S;Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117576, Singapore.;Shenzhen Univ, SZU NUS Collaborat Innovat Ctr Optoelect Sci & Te, Shenzhen 518060, Peoples R China.;NUS Suzhou Res Inst NUSRI, Suzhou Ind Pk, Suzhou 215123, Peoples R China.
关键词：
geometric phase;spin Hall effect of light;spin Hall shift;weak measurements
摘要：
The spin Hall effect (SHE) of light, as an analogue of the SHE in electronic systems, is a promising candidate for investigating the SHE in semiconductor spintronics/valleytronics, high-energy physics and condensed matter physics, owing to their similar topological nature in the spin-orbit interaction. The SHE of light exhibits unique potential for exploring the physical properties of nanostructures, such as determining the optical thickness, and the material properties of metallic and magnetic thin films and even atomically thin two-dimensional materials. More importantly, it opens a possible pathway for controlling the spin states of photons and developing next-generation photonic spin Hall devices as a fundamental constituent of the emerging spinoptics. In this review, based on the viewpoint of the geometric phase gradient, we give a detailed presentation of the recent advances in the SHE of light and its applications in precision metrology and future spin-based photonics. © 2017 IOP Publishing Ltd.
语种：
英文
展开
Visible-Frequency Metasurface for Structuring and Spatially Multiplexing Optical Vortices
作者：
Mehmood, M. Q.;Mei, Shengtao;Hussain, Sajid;Huang, Kun;Siew, S. Y.;...
期刊：
Advanced Materials ,2016年28(13):2533-2539 ISSN：0935-9648
通讯作者：
Qiu, Cheng-Wei
作者机构：
[Mei, Shengtao; Mehmood, M. Q.; Zhang, Tianhang; Ling, Xiaohui; Zhang, Lei; Qiu, Cheng-Wei; Hussain, Sajid; Danner, Aaron; Siew, S. Y.] Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117583, Singapore.;[Mei, Shengtao; Qiu, Cheng-Wei] Natl Univ Singapore, Ctr Life Sci CeLS, Grad Sch Integrat Sci & Engn, 05-01,28 Med Dr, Singapore 117456, Singapore.;[Liu, Hong; Huang, Kun; Teng, Jinghua] Innovis, A STAR, Inst Mat Res & Engn, 08-03,2 Fusionopolis Way, Singapore 138634, Singapore.;[Ling, Xiaohui] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Zhang, Shuang] Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England.
通讯机构：
[Qiu, Cheng-Wei] N;Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117583, Singapore.;Natl Univ Singapore, Ctr Life Sci CeLS, Grad Sch Integrat Sci & Engn, 05-01,28 Med Dr, Singapore 117456, Singapore.
关键词：
babinet-inverted;metalens;multifocus;optical-vortex beam;topological charge
摘要：
A multifocus optical vortex metalens, with enhanced signal-to-noise ratio, is presented, which focuses three longitudinal vortices with distinct topological charges at different focal planes. The design largely extends the flexibility of tuning the number of vortices and their focal positions for circularly polarized light in a compact device, which provides the convenience for the nanomanipulation of optical vortices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
语种：
英文
展开
Giant photonic spin Hall effect in momentum space in a structured metamaterial with spatially varying birefringence
作者：
Ling, Xiaohui;Zhou, Xinxing;Yi, Xunong;Shu, Weixing;Liu, Yachao;...
期刊：
光：科学与应用 ,2015年4(5):e290 ISSN：2095-5545
通讯作者：
Luo, Hailu
作者机构：
[Fan, Dianyuan; Shu, Weixing; Wen, Shuangchun; Luo, Hailu; Zhou, Xinxing; Ling, Xiaohui; Liu, Yachao; Chen, Shizhen] Hunan Univ, Sch Phys & Elect, Lab Spin Photon, Changsha 410082, Hunan, Peoples R China.;[Ling, Xiaohui] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421002, Peoples R China.;[Fan, Dianyuan; Yi, Xunong; Ling, Xiaohui] Shenzhen Univ, SZU NUS Collaborat Innovat Ctr Optoelect Sci & Te, Shenzhen 518060, Peoples R China.;[Fan, Dianyuan; Yi, Xunong; Ling, Xiaohui] Shenzhen Univ, Key Lab Optoelect Devices & Syst, Minist Educ & Guangdong Prov, Shenzhen 518060, Peoples R China.
通讯机构：
[Luo, Hailu] H;Hunan Univ, Sch Phys & Elect, Lab Spin Photon, Changsha 410082, Hunan, Peoples R China.
关键词：
geometric phase;metamaterial;photonic spin Hall effect
摘要：
The photonic spin Hall effect (SHE) in the reflection and refraction at an interface is very weak because of the weak spin-orbit interaction. Here, we report the observation of a giant photonic SHE in a dielectric-based metamaterial. The metamaterial is structured to create a coordinate-dependent, geometric Pancharatnam Berry phase that results in an SHE with a spin-dependent splitting in momentum space. It is unlike the SHE that occurs in real space in the reflection and refraction at an interface, which results from the momentum-dependent gradient of the geometric Rytov Vladimirskii Berry phase. We theorize a unified description of the photonic SHE based on the two types of geometric phase gradient, and we experimentally measure the giant spin-dependent shift of the beam centroid produced by the metamaterial at a visible wavelength. Our results suggest that the structured metamaterial offers a potential method of manipulating spin-polarized photons and the orbital angular momentum of light and thus enables applications in spin-controlled nanophotonics. © 2015 CIOMP.
语种：
英文
展开
