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electronic transport properties of phenylacetylene molecular junctions

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Chinese Physics B 2011年第10期20卷 384-389页

作者：刘文程杰闫翠霞李海宏王永娟刘德胜 Physics and Information Engineering Department Jining University School of Physics Shandong University

electronic transport properties of a kind of phenylacetylene compound-- （4-mercaptophenyl）-phenylacetylene are calculated by the first-principles method in the framework of density functional theory and the nonequilibrium Green＇s function formalism. The molecular junction shows an obvious rectifying behaviour at a bias voltage larger than 1.0 V. The rectification effect is attributed to the asymmetry of the interface contacts. Moreover, at a bias voltage larger than 2.0 V, which is not referred to in a relevant experiment [Fang L, Park J Y, Ma H, Jen A K Y and Salmeron M 2007 Langmuir 23 11522], we find a negative differential resistance phenomenon. The negative differential resistance effect may originate from the change of the delocalization degree of the molecular orbitals induced by the bias.

关键词： phenylacetylene compound electronic transport rectification

electronic transport through a periodic array of quantum-dot rings

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Chinese Physics B 2010年第4期19卷 381-387页

作者：薛海斌张瀚尹聂一行李志坚梁九卿 Institute of Theoretical Physics and Department of Physics Shanxi University Institute of Solid State Physics Shanxi Datong University

Using the tight-binding approximation and the transfer matrix method, this paper studies the electronic transport properties through a periodic array of quantum-dot （QD） rings threaded by a magnetic flux. It demonstrates that the even^odd parity of the QD number in a single ring and the number of the QD rings in the array play a crucial role in the electron transmission. For a single QD ring, the resonance and antiresonance transmission depend not only on the applied magnetic flux but also on the difference between the number of QDs on the two arms of the ring. For an array of QD rings, the transmission properties are related not only to the even-odd parity of the number No of QDs in the single ring but also to the even-odd parity of the ring number N in the array. When the incident electron energy is aligned with the site energy, for the array of N rings with No = odd the antiresonance transmission cannot occur but the resonance transmission may occur and the transmission spectrum has N resonance peaks （N - 1 resonance peaks） in a period for N = odd （for N = even）. For the array of N rings with No = even the transmission properties depend on the flux threading the ring and the QD number on one arm of the ring. These results may be helpful in designing QD devices.

关键词： quantum dots electronic transport antiresonance transmission resonance transmission

electronic transport properties of single-wall boron nanotubes

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Chinese Physics B 2017年第8期26卷 438-443页

作者：代新月周毅李洁张力舒赵珍阳李辉 Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China

electronic transport properties of single-wall boron nanotube （BNT） with different chiralities, diameters, some of which are encapsulated with silicon, germanium, and boron nanowires are theoretically studied. The results indicate that the zigzag （3,3） BNT has more electronic transmission channels than the armchair （5,0） BNT because of its unique structure distortion. Nanowires encapsulated in the BNT can enhance the conductance of the BNT to some extent by providing a significant electronic transmission channel to the BNT. The effect of the structure of nanowires and the diameter of BNTs on the transport properties has also been discussed. The results of this paper can enrich the knowledge of the electron transport of the BNT and provide theoretical guidance for subsequent experimental study.

关键词： electronic transport boron nanoube BNT

electronic transport for armchair graphene nanoribbons with a potential barrier

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Chinese Physics B 2010年第3期19卷 482-485页

作者：周本胡段子刚周本良周光辉 Department of Physics Hunan Normal University Institute of Optoelectronics Shenzhen University

This paper studies the electronic transport property through a square potential barrier in armchair-edge graphene nanoribbon （AGNR）. Using the Dirac equation with the continuity condition for wave functions at the interfaces between regions with and without a barrier, we calculate the mode-dependent transmission probability for both semiconducting and metallic AGNRs, respectively. It is shown that, by some numerical examples, the transmission probability is generally an oscillating function of the height and range of the barrier for both types of AGNRs. The main difference between the two types of systems is that the magnitude of oscillation for the semiconducting AGNR is larger than that for the metallic one. This fact implies that the electronic transport property for AGNRs depends sensitively on their widths and edge details due to the Dirac nature of fermions in the system.

关键词： armchair-edge graphene nanoribbon potential barrier electronic transport

electronic transport of the Adsorbed Trigonal Graphene Flake： A First Principles Calculation

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Chinese Physics Letters 2014年第12期31卷 99-102页

作者：谭勋琼 School of Physics and electronic Science Changsha University of Science and Technology Changsha 410114

In recent years, electronic transport through molecular devices has attracted much attention due to the progress in experimental techniques for ma- nipulating individual molecules and the availabil- ity of the first-principles method to describe the elec- trical properties of devices. Graphene, a two- dimensional （2D） network of sp2 hybridized carbon atoms, has stimulated great research interest due to its unique electronic transport properties and its pro- found potential for future device applications. Chemical doping with foreign atoms is generally cho- sen to modify the electronic transport properties of carbon materials. The possibility of functionalizing graphene with radicals such as O, F, and H atoms has been experimentally demonstrated. One- dimensional GNRs and zero-dimensional graphene quantum dots （GQDs）, including triangular, rectangular and hexagonal shapes, which can be ob- tained through the geometry cutting method, pro- vide the possibility to explore low-dimensional trans- port properties for carbon-based nanoelectronics. The trigonal graphene flake （TGF）, a kind of representa- tive zero-dimensional GQD, is prominent in electronic and magnetic properties due to its n-fold degenerated half-filled zero-energy states. This novel property was revealed by both experimental and theoretical studies.

关键词： electronic transport Adsorbed Trigonal Graphene First Principles Calculation

electronic transport properties of topological insulator films and low dimensional superconductors

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Frontiers of physics 2013年第5期8卷 491-508页

作者：邢颖孙平书 MeenakshiSingh 赵弁斐 MosesH.W.Chan 王健 International Center for Quantum Materials School of Physics Peking University Beijing 100871 China The Center for Nanoscale Science and Department of Physics The Pennsylvania State University University Park PA 16802-6300 USA

In this review, we present a summary of some recent experiments on topological insulators （TIs） and superconducting nanowires and fihns. Electron electron interaction （EEI）, weak anti-localization （WAL） and anisotropic magneto-resistance （AMR） effect fbund in topological insulator fihns by transport measurements are reported. Then, transport properties of superconducting films, bridges and nanowires and proximity effect in non-superconducting nanowires are described. Finally, the interplay between topological insulators and superconductors （SCs） is also discussed.

关键词： electronic transport topological insulator superconductor low dimensional

Preparation of PSFO and LPSFO nanofibers by electrospinning and their electronic transport and magnetic properties

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Chinese Physics B 2022年第5期31卷 629-635页

作者： Ying Su Dong-Yang Zhu Ting-Ting Zhang Yu-Rui Zhang Wen-Peng Han Jun Zhang Seeram Ramakrishna Yun-Ze Long Collaborative Innovation Center for Nanomaterials&Devices College of PhysicsQingdao UniversityQingdao 266071China Center for Nanofibers&Nanotechnology Department of Mechanical EngineeringNational University of SingaporeSingapore 117574Singapore Collaborative Innovation Center for Eco-Textiles of Shandong Province and State Key Laboratory of Bio-Fibers and Eco-TextilesQingdao UniversityQingdao 266071China

Pr_(0.5)Sr_(0.5)FeO_(3)(PSFO)and La_(0.25)Pr_(0.25)Sr_(0.5)FeO_(3)(LPSFO)nanofibers are prepared by electrospinning followed by calcination,and their morphologies,microstructures,electronic transports,and magnetic properties are studied *** temperature-dependent resistance curves of PSFO and LPSFO nanofibers are measured in a temperature range from 300 K to 10 *** the temperature lowering,the resistance increases gradually and then decreases sharply due to the occurrence of ferromagnetic metal *** metal-insulator transition temperatures are about 110 K and 180 K for PSFO and LPSFO nanofibers,*** electronic conduction behavior above the transition temperature can be described by one-dimensional Mott’s variable-range hopping(VRH)*** hysteresis loops and the field-cooled(FC)and zero-field-cooled(ZFC)curves show that both PSFO nanofiber and LPSFO nanofiber exhibit *** the doping of La reduces the overall magnetization intensity of the material,it increases the ferromagnetic ratio of the system,which may improve the performance of LPSFO in solid oxide fuel cell.

关键词： Pr_(0.5)Sr_(0.5)FeO_(3) La_(0.25)Pr_(0.25)Sr_(0.5)FeO_(3) electrospinning electronic transport magnetic properties

Magnetically Controlled electronic transport Properties of a Ferromagnetic Junction on the Surface of a Topological Insulator

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Communications in Theoretical Physics 2015年第6期63卷 777-782页

作者：刘正钦王瑞强邓明勋胡梁宾 Laboratory of Quantum Information Technology ICMP and SPTESouth China Normal University

We have investigated the transport properties of the Dirac fermions through a ferromagnetic barrier junction on the surface of a strong topologicM insulator. The current-voltage characteristic curve and the tunneling conductance are calculated theoretically. Two interesting transport features are predicted： observable negative differential conductances and linear conductances tunable from unit to nearly zero. These features can be magnetically manipulated simply by changing the spacial orientation of the magnetization. Our results may contribute to the development of high-speed switching and functional applications or electricalIy controlled magnetization switching.

关键词： topological insulator electronic transport negative differential conductance magnetic switch

electronic transport Through N24B24 Molecular Junction

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Chinese Journal of Chemical Physics 2016年第2期29卷 223-228,I0002页

作者： Mojtaba Yaghobi Mohammad Ali Ramzanpour MohammadReza Nyazian 伊朗伊斯兰自由大学阿莫尔

We have investigated the electron transport properties of a N24B24 molecule coupled to two metallic contacts with a combination of GW approximation and the non-equilibrium Green＇s- function technique. The calculations indicate that the four and three resonant tunneling peaks are seen for the density of states （DOS） curves in the cases of single and multiple atomic contacts, respectively. The off state and negative differential resistance （NDR） effect are observed in the I-V characteristics of the N24B24 molecule. The NDR behavior is also observed in voltages of about 354.5, 354, 354.6, and 354.3 V for one, four, six, and eight atomic contacts. Also, the I-V characteristics of N24B24 are in off state at low voltages that is independent of the contact types. The current contact types and indicate that N24B24 molecule curves against the gate voltage depend on behaves as a semiconductor.

关键词： Boron Nitride Cage electronic transport Non-equilibrium Green's function