检索结果-内蒙古大学图书馆

Cr doping induced negative transverse magnetoresistance in Cd3As2 thin films

Physical Review B 2018年第8期97卷 085303-085303页

作者： Yanwen Liu Rajarshi Tiwari Awadhesh Narayan Zhao Jin Xiang Yuan Cheng Zhang Feng Chen Liang Li Zhengcai Xia Stefano Sanvito Peng Zhou Faxian Xiu State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 China Institute for Nanoelectronic Devices and Quantum Computing Fudan University Shanghai 200433 China School of Physics AMBER and CRANN Institute Trinity College Dublin 2 Ireland Department of Physics University of Illinois at Urbana-Champaign Champaign Illinois USA 61801 Materials Theory ETH Zurich Wolfgang-Pauli-Strasse 27 CH 8093 Zurich Switzerland Wuhan National High Magnetic Field Center Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of ASIC and System Department of Microelectronics Fudan University Shanghai 200433 China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093 China

The magnetoresistance of a material conveys various dynamic information about charge and spin carriers, inspiring both fundamental studies in physics and practical applications such as magnetic sensors, data storage, and spintronic devices. Magnetic impurities play a crucial role in the magnetoresistance as they induce exotic states of matter such as the quantum anomalous Hall effect in topological insulators and tunable ferromagnetic phases in dilute magnetic semiconductors. However, magnetically doped topological Dirac semimetals are hitherto lacking. Here, we report a systematic study of Cr-doped Cd3As2 thin films grown by molecular-beam epitaxy. With the Cr doping, Cd3As2 thin films exhibit unexpected negative transverse magnetoresistance and strong quantum oscillations, bearing a trivial Berry's phase and an enhanced effective mass. More importantly, with ionic gating the magnetoresistance of Cr-doped Cd3As2 thin films can be drastically tuned from negative to positive, demonstrating the strong correlation between electrons and the localized spins of the Cr impurities, which we interpret through the formation of magnetic polarons. Such a negative magnetoresistance under perpendicular magnetic field and its gate tunability have not been observed previously in the Dirac semimetal Cd3As2. The Cr-induced topological phase transition and the formation of magnetic polarons in Cd3As2 provide insights into the magnetic interaction in Dirac semimetals as well as their potential applications in spintronics.

关键词： Growth Magnetoresistance Dirac semimetal Density functional theory Shubnikov-de Haas effect

来源：评论

学校读者我要写书评

暂无评论

Characterization of vertical Au/β-Ga_2O_3 single-crystal Schottky photodiodes with MBE-grown high-resistivity epitaxial layer

引用

Chinese Physics B 2016年第1期25卷 757-761页

作者：刘兴钊岳超夏长泰张万里 State Key Laboratory of Electronic Thin Films and Integrated Devices School of Microelectronics and Solid-State ElectronicsUniversity of Electronic Science and Technology of China Key Laboratory of Materials for High Power Laser Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences

High-resistivity β-Ga203 thin films were grown on Si-doped n-type conductive β-Ga203 single crystals by molecular beam epitaxy （MBE）. Vertical-type Schottky diodes were fabricated, and the electrical properties of the Schottky diodes were studied in this letter. The ideality factor and the series resistance of the Schottky diodes were estimated to be about 1.4 and 4.6 x 10^6 %. The ionized donor concentration and the spreading voltage in the Schottky diodes region are about 4 x 10^18 cm-3 and 7.6 V, respectively. The ultra-violet （UV） photo-sensitivity of the Schottky diodes was demonstrated by a low-pressure mercury lamp illumination. A photoresponsivity of 1.8 A/W and an external quantum efficiency of 8.7 x 10%2% were observed at forward bias voltage of 3.8 V, the proper driving voltage of read-out integrated circuit for UV camera. The gain of the Schottky diode was attributed to the existence of a potential barrier in the i-n junction between the MBE-grown highly resistive β-Ga203 thin films and the n-type conductive β-Ga203 single-crystal substrate.

关键词： gallium oxides thin films Schottky diode ultraviolet photodetector

来源：评论

学校读者我要写书评

暂无评论

Anderson transition of two-dimensional spinful electrons in the Gaussian unitary ensemble

引用

Physical Review B 2017年第10期96卷 104204-104204页

作者： C. Wang X. R. Wang School of Microelectronics and Solid-State Electronics and State Key Laboratory of Electronic Thin Film and Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China Physics Department The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong HKUST Shenzhen Research Institute Shenzhen 518057 China

We study the Anderson localization of disordered two-dimensional electron gases (2DEGs) on a square lattice subject to a perpendicular magnetic field B, random scalar potentials, and Rashba spin-orbit interactions. Our focus is on the weak magnetic field region, motivated by the intriguing question of how those extended states, existing in the absence of the magnetic field (B=0) when the 2DEGs are the Gaussian symplectic ensemble, change with B. Using highly accurate numerical procedures based on the transfer matrix technique and the level statistics, we found that a metallic phase exists at weak magnetic fields, in contrast to the predictions of the one-parameter scaling theory that all states are localized at weak fields except at zero field, and the metallic phase evolves continuously into those at strong magnetic fields. A schematic phase diagram drawn in the field-energy plane elucidates the occurrence and evolution of extended states.

关键词： Anderson localization Critical exponents Critical phenomena Landau levels Quantum phase transitions Rashba coupling

来源：评论

学校读者我要写书评

暂无评论

Simulation study of an enhancement-mode n-type InGaAs MOSFETs with a low zero bias off-current 7

Simulation study of an enhancement-mode n-type InGaAs MOSFET...

引用

7th IEEE International Nanoelectronics Conference, INEC 2016

作者： Gong, Zhujing Chang, Hudong Wang, Shengkai Li, Yue Sun, Bing Liu, Honggang Microwave Device IC Department Institute of Microelectronics Chinese Academy of Science Beijing100029 China Key Laboratory of Microelectronics Devices and Integrated Technology Institute of Microelectronics Chinese Academy of Science Beijing100029 China

ISBN: (纸本)9781467389693

InGaAs channel metal-oxide-semiconductor field-effect transistors (MOSFETs) with thin channels and wide-bandgap InP vertical field spacers in the S/D have been simulated and investigated. I-V characteristics and leakage current are carefully studied. Good performance can be achieved by controlling indium concentration of InGaAs channel, delta doping concentration and InP caplayer thickness. Simulation results show that an enhancement-mode n-type InGaAs MOSFETs with a low zero bias off-current La can be achieved. An InGaAs MOSFET with Lg=450nm has been made and the measured data fit well with the simulated results. © 2016 IEEE.

关键词： MOSFET devices

来源：评论

学校读者我要写书评

暂无评论

Design and Optimization of Four-Region Multistep Field Limiting Rings for 10kV 4H-SiC IGBTs

Design and Optimization of Four-Region Multistep Field Limit...

引用

IEEE International Conference on Solid-State and Integrated Circuit technology

作者： Ben Tan Xiao-Li Tian Jiang Lu Yun Bai Xiao-Chuan Deng Cheng-Zhan Li Xin-Yu Liu High-Frequency High-Voltage Devices and Integrated Circuits R&D Center Institute of Microelectronics of Chinese Academy of Sciences Beijing China The State Key Laboratory of Electronic Thin Films and Integrated Devices School of Microelectronics and Solid-State Electronics University of Electronic Science and Technology of China Chengdu China ZhuZhou CRRC Times Electric Co. Ltd ZhuZhou China

A novel edge termination structure with Four-Region Multistep Field Limiting Rings (FRM-FLRs) is proposed and investigated for lOkV 4H-SiC IGBTs. The structure with FRM-FLRs terminal technology exhibits a good blocking performance with 30% less terminal area and 23% higher blocking voltage compared with the conventional Filed limiting Rings (Con-FLRs) structure. Moreover, the structure with FRM-FLRs can decrease the sensitivity of the interface charges, which greatly improves the reliability of the device at the off-state.

关键词： proposed investigated lOkV

来源：评论

学校读者我要写书评

暂无评论

Magnetic proximity effect in graphene coupled to a BiFeO3 nanoplate

引用

Physical Review B 2017年第19期95卷 195426-195426页

作者： Yan-Fei Wu Hua-Ding Song Liang Zhang Xin Yang Zhaohui Ren Dameng Liu Han-Chun Wu Jansheng Wu Jin-Guang Li Zhenzhao Jia Baoming Yan Xiaosong Wu Chun-Gang Duan Gaorong Han Zhi-Min Liao Dapeng Yu Institute for Quantum Science and Engineering and Department of Physics South University of Science and Technology of China Shenzhen 518055 China State Key Laboratory for Mesoscopic Physics School of Physics Peking University Beijing 100871 China State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 China State Key Laboratory of Tribology Tsinghua University Beijing 100084 China School of Physics Beijing Institute of Technology Beijing 100081 China Collaborative Innovation Center of Quantum Matter Beijing 100871 China Key Laboratory of Polar Materials and Devices Ministry of Education East China Normal University Shanghai 200241 China

Graphene, a very intriguing two-dimensional Dirac electronic system with high carrier mobility, is promising for spintronics. However, the long-range ferromagnetic order is always absent in pristine graphene. Here we report the fabrication and transport properties of graphene-BiFeO3 heterostructures. It is found that the magnetic proximity effect results in a strong Zeeman splitting in graphene with the exchange field up to hundreds of tesla. The ν=0 quantum Hall state of graphene is further transformed into a ferromagnetic state or a canted antiferromagnetic state in the presence of a perpendicular magnetic field. Our findings in graphene/BiFeO3 heterostructure are therefore promising for future spintronics.

关键词： Antiferromagnetism Dirac fermions Edge states Electrical conductivity Graphene Transmission electron microscopy

来源：评论

学校读者我要写书评

暂无评论

Symbol error rate performance analysis of soft-decision decoded MPPM free space optical system over exponentiated Weibull fading channels

引用

Chinese Optics Letters 2017年第5期15卷 21-25页

作者：周端曹天杨银堂张剑贤王平杨本圣 School of Computer Science and Technology Xidian University Xi'an 710071 China State Key Laboratory of Integrated Service Networks School of Telecommunications Engineering Xidian University Xi'an 710071 China Southwest China Research Institute of Electronic Equipment Chengdu 610036 China Key Laboratory of the Ministry of Education for Wide Band-Cap Semiconductor Materials and Devices School of Microelectronics Xidian University Xi'an 710071 China School of Physics and Optoelectronic Engineering Xidian University Xi'an 710071 China

The symbol error rate （SER） performance of a multipulse pulse-position modulation （MPPM） free space optical （FSO） system under the combined effect of turbulence-induced fading modeled by exponentiated Weibull （EW） distribution and pointing errors with a soft-decision detector is investigated systematically. Particularly, the theoretical conditional SER （CSER） of soft-decision decoded MPPM is derived. The corresponding closed-form CSER is obtained via curve fitting with the Levenberg-Marquardt method. The analytical SER expression over the aggregated fading channels is then achieved in terms of Laguerre integration. Monte Carlo simulation results are also offered to corroborate the validity of the proposed SER model.

关键词： Curve fitting Decoding Errors Intelligent systems Monte Carlo methods Optical communication Optical systems Weibull distribution

来源：评论

学校读者我要写书评

暂无评论

Aharonov-Bohm effect in monolayer phosphorene nanorings

引用

Physical Review B 2017年第12期95卷 125418-125418页

作者： Rui Zhang Zhenhua Wu X. J. Li Kai Chang SKLSM Institute of Semiconductors Chinese Academy of Sciences 100083 Beijing China College of Materials Science and Opto-Electronic Technology University of Chinese Academy of Sciences 100049 Beijing China Key Laboratory of Microelectronic Devices and Integrated Technology Institute of Microelectronics Chinese Academy of Sciences 100029 Beijing China College of Physics and Energy Fujian Normal University 350007 Fuzhou China

This work presents a theoretical demonstration of the Aharonov-Bohm (AB) effect in monolayer phosphorene nanorings (PNRs). Atomistic quantum transport simulations of PNRs are employed to investigate the impact of multiple modulation sources on the sample conductance. In the presence of a perpendicular magnetic field, we find that the conductance of both armchair and zigzag PNRs oscillate periodically in a low-energy window as a manifestation of the AB effect. Our numerical results reveal a giant magnetoresistance (MR) in zigzag PNRs (with a maximum magnitude approaching 2000%). It is attributed to the AB-effect-induced destructive interference phase over a wide energy range below the bottom of the second subband. We also demonstrate that PNR conductance is highly anisotropic, offering an additional way to modulate MR. The giant MR in PNRs is maintained at room temperature in the presence of the thermal broadening effect.

关键词： Ballistic transport Electrical conductivity Magnetoelectric effect Magnetotransport Semiconductors Transport phenomena

来源：评论

学校读者我要写书评

暂无评论

Tunable transfer behaviors of single-layer WSe＿2 field effect transistors by hydrazine 13

Tunable transfer behaviors of single-layer WSe＿2 field effe...

引用

2016 13th IEEE International Conference on Solid-State and Integrated Circuit technology (ICSICT)

作者： Mengxing Sun Dan Xie Yilin Sun Zhixin Li Jianlong Xu Ruixuan Dai Xian Li Cheng Zhang Changjiu Teng Pu Yang Institute of Microelectronics and Tsinghua National Laboratory for Information Science and Technology (TNList) Tsinghua University Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices Soochow University

ISBN: (纸本)9781467397209

Polarity modulation of single-layer WSe2 field effect transistor is investigated by using hydrazine as a solution-processable and effective n-type dopant for WSe2. Compared to the intrinsic hole-dominant ambipolar behaviors, highly effective n-type doping characteristics are achieved after hydrazine treatment. It is found that the on-current improves obviously by one order of magnitude and the metal-WSe2 contact resistance decreases at the same time. After hydrazine being removed, the electron doping effect disappears which indicates hydrazine treatment is a reversible doping process. This work provides a possibility for transition metal dichalcogenides-based logic device applications in the future.

关键词： Tunable transfer behaviors of single-layer WSe field effect transistors by hydrazine

来源：评论

学校读者我要写书评

暂无评论

Tuning electrical and optical anisotropy of a monolayer black phosphorus magnetic superlattice

arXiv

引用

arXiv 2017年

作者： Li, X.J. Yu, J.H. Wu, Z.H. Yang, W. College of Physics and Energy Fujian Normal University Fuzhou350117 China Key Laboratory of Microelectronic Devices and Integrated Technology Institute of Microelectronics Chinese Academy of Sciences Beijing100029 China Beijing Computational Science Research Center Beijing100094 China

We investigate theoretically the effects of modulated periodic perpendicular magnetic fields on the electronic states and optical absorption spectrum in a monolayer black phosphorus (phosphorene). We demonstrate that different phosphorene magnetic superlattice (PMS) orientations can give rise to distinct energy spectra, i.e., tuning the intrinsic electronic anisotropy. The Rashba spin-orbit coupling (RSOC) will develop a spin-splitting energy dispersion in this phosphorene magnetic supperlattice. Anisotropic momentum-dependent carrier distributions along/perpendicular to the magnetic strips are demonstrated, and the manipulations of these exotic properties by tuning superlattice geometry, magnetic field and the RSOC term (via an external electric field) are addressed systematically. Accordingly, we find bright-to-dark transitions in the ground state electron-hole pairs transition rate spectrum and PMS orientation dependent anisotropic optical absorption spectrum. This feature offers us a practical way to modulate the electronic anisotropy in phosphorene by magnetic superlattice configurations and detect these modulation capability by using the optical technique. Copyright © 2017, The Authors. All rights reserved.

关键词： Monolayers

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：