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Organic molecules modified palladium nanowires arrays prepared by high temperature liquid phase reduction

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Chinese Physics B 2008年第6期17卷 2191-2196页

作者：申承民杨天中肖从文张怀若田继发鲍丽宏李晨李建奇高鸿钧 Beijing National Laboratory for condensed matter Physics Institute of Physics Chinese Academy of Sciences

This paper reports high temperature liquid phase synthesis of Pd nanowires using chemically modified porous anodic aluminium oxide as template. In this synthesis process, oleic acid is used to modify the inner wall of the pores and Pd^2＋ complex with oleylamine is filled into the channel of the template. The complex is then reduced to give oleylamine-capped Pd nanowires. This paper suggests that oleic acid can improve the environment of inner wall of the pores, leading to the formation of uniform Pd nanowires. The synthetic process can be extended to make other types of nanowires.

关键词： palladium nanowires anodic aluminium oxide template oleylamine-capped

Manipulation and control of a single molecular rotor on Au(111) surface

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Chinese Physics B 2010年第1期19卷 538-543页

作者：张海刚毛金海刘奇江楠周海涛郭海明时东霞高鸿钧 Beijing National Laboratory of condensed matter Physics Institute of PhysicsChinese Academy of Sciences

Three different methods are used to manipulate and control phthalocyanine based single molecular rotors on Au （111） surface：（1） changing the molecular structure to alter the rotation potential; （2） using the tunnelling current of the scanning tunnelling microscope （STM） to change the thermal equilibrium of the molecular rotor; （3） artificial manipulation of the molecular rotor to switch the rotation on or off by an STM tip. Furthermore, a molecular ＇gear wheel＇ is successfully achieved with two neighbouring molecules.

关键词： single molecular rotor scanning tunnelling microscope single-molecule manipulation

Metallic nanowires for subwavelength waveguiding and nanophotonic devices

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Chinese Physics B 2013年第9期22卷 72-83页

作者：潘登魏红徐红星 Beijing National Laboratory for condensed matter Physics and institute of Physics Chinese Academy of Sciences

Plasmonics is a rapidly developing field concerning light manipulation at the nanoscale with many potential applica- tions, of which plasmonic circuits are promising for future information technology. Plasmonic waveguides are fundamental elements for constructing plasmonic integrated circuits. Among the proposed different plasmonic waveguides, metallic nanowires have drawn much attention due to the highly confined electromagnetic waves and relatively low propagation loss. Here we review the recent research progress in the waveguiding characteristics of metallic nanowires and nanowire-based nanophotonic devices. Plasmon modes of both cylindrical and pentagonal metallic nanowires with and without substrate are discussed. Typical methods for exciting and detecting the plasmons in metallic nanowires are briefly summarized. Be- cause of the multimode characteristic, the plasmon propagation and emission in the nanowire have many unique properties, benefiting the design of plasmonic devices. A few nanowire-based devices are highlighted, including quarter-wave plate, Fabry-Pdrot resonator, router and logic gates.

关键词： surface plasmons waveguide circuit nanowire

Electron localization in ultrathin films of three-dimensional topological insulators

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Chinese Physics B 2016年第11期25卷 19-25页

作者：廖剑史刚刘楠李永庆 Beijing National Laboratory for condensed matter Physics Institute of PhysicsChinese Academy of Sciences

The recent discovery of three-dimensional（3D） topological insulators（TIs） has provided a fertile ground for obtaining further insights into electron localization in condensed matter *** the past few years,a tremendous amount of research effort has been devoted to investigate electron transport properties of 3D TIs and their low dimensional structures in a wide range of disorder strength,covering transport regimes from weak antilocalization to strong *** knowledge gained from these studies not only offers sensitive means to probe the surface states of 3D TIs but also forms a basis for exploring novel topological *** this article,we briefly review the main experimental progress in the study of the localization in 3D TIs,with a focus on the latest results on ultrathin TI *** new transport data will also be presented in order to complement those reported previously in the literature.

关键词： topological localization devoted covering complement Electron briefly tremendous crossover coherent

Microstructure and structural phase transitions in iron-based superconductors

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Chinese Physics B 2013年第8期22卷 123-134页

作者：王臻蔡瑶杨槐馨田焕芳王秩伟马超陈震李建奇 Beijing National Laboratory for condensed matter Physics Institute of Physics Chinese Academy of Sciences

Crystal structures and microstructural features, such as structural phase transitions, defect structures, and chemical and structural inhomogeneities, are known to have profound effects on the physical properties of superconducting materials. Recently, many studies on the structural properties of Fe-based high-Tc superconductors have been published. This review article will mainly focus on the typical microstructural features in samples that have been well characterized by physical measurements. （i） Certain common structural features are discussed, in particular, the crystal structural features for different superconducting families, the local structural distortions in the Fe2Pn2 （Pn = P, As, Sb） or FeeCh2 （Ch = S, Se, Te） blocks, and the structural transformations in the 122 system. （ii） In FeTe（Se）（11 family）, the superconductivity, chemical and structural inhomogeneities are investigated and discussed in correlation with superconductivity. （iii） In the ***1.6＋xSe2 system, we focus on the typical compounds with emphasis on the Fe-vacancy order and phase separations. The microstructural features in other superconducting materials are also briefly discussed.

关键词： Fe-based superconductor structural transition structural inhomogeneity phase separation

A Green’s function model for ferromagnetism and spin excitations of (Ga, Mn)As diluted magnetic semiconductors

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Chinese Physics B 2009年第11期18卷 5047-5054页

作者：刘贵斌刘邦贵 institute of Physics Chinese Academy of Sciences Beijing National Laboratory for condensed matter Physics

We study （Ga, Mn）As diluted magnetic semiconductors in terms of the Ruderman-Kittel-Kasuya-Yosida quantum spin model in Green＇s function approach. Random distributions of the magnetic atoms are treated by using an analytical average of magnetic configurations. Average magnetic moments and spin excitation spectra as functions of temperature can be obtained by solving self-consistent equations, and the Curie temperature TC is given explicitly. Tc is proportional to magnetic atomic concentration, and there exists a maximum for Tc as a function of carrier concentration. Applied to （Ga, Mn）As, the theoretical results are consistent with experiment and the experimental TC can be obtained with reasonable parameters. This modelling can also be applied to other diluted magnetic semiconductors.

关键词： diluted magnetic semiconductor Green's function Ruderman-Kittel-Kasuya-Yosida

An improved loopless mounting method for cryocrystallography

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Chinese Physics B 2010年第1期19卷 212-221页

作者：齐建勋江凡 Beijing National Laboratory for condensed matter Physics Institute of PhysicsChinese Academy of Sciences

Based on a recent loopless mounting method, a simplified loopless and bufferless crystal mounting method is developed for macromolecular crystallography. This simplified crystal mounting system is composed of the following components： a home-made glass capillary, a brass seat for holding the glass capillary, a flow regulator, and a vacuum pump for evacuation. Compared with the currently prevalent loop mounting method, this simplified method has almost the same mounting procedure and thus is compatible with the current automated crystal mounting system. The advantages of this method include higher signal-to-noise ratio, more accurate measurement, more rapid flash cooling, less x-ray absorption and thus less radiation damage to the crystal. This method can be extended to the flash-freeing of a crystal without or with soaking it in a lower concentration of cryoprotectant, thus it may be the best option for data collection in the absence of suitable cryoprotectant. Therefore, it is suggested that this mounting method should be further improved and extensively applied to eryocrystallographic experiments.

关键词： cryoprotectant crystal mounting data collection flash cooling

Antiferromagnetism and Kondo screening on a honeycomb lattice

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Chinese Physics B 2015年第5期24卷 489-497页

作者：林恒福陶红帅郭文祥刘伍明 Beijing National Laboratory for condensed matter Physics Institute of Physics Chinese Academy of Sciences

Magnetic adatoms in the honeycomb lattice have received tremendous attention due to the interplay between Ruderman-Kittel-Kasuya-Yosida interaction and Kondo coupling leading to very rich physics. Here we study the competition between the antiferromagnetism and Kondo screening of local moments by the conduction electrons on the honeycomb lattice using the determinant quantum Monte Carlo method. While changing the interband hybridization V, we systemat- ically investigate the antiferromagnetic-order state and the Kondo singlet state transition, which is characterized by the behavior of the local moment, antiferromagnetic structure factor, and the short range spin-spin correlation. The evolution of the single particle spectrum are also calculated as a function of hybridization V, we find that the system presents a small gap in the antiferromagnetic-order region and a large gap in the Kondo singlet region in the Fermi level. We also find that the localized and itinerant electrons coupling leads to the midgap states in the conduction band in the Fermi level at very small V. Moreover, the formation of antiferromagnetic order and Kondo singlet are studied as on-site interaction U or temperature T increasing, we have derived the phase diagrams at on-site interaction U （or temperature T） and hybridization V plane.

关键词： periodic Anderson model antiferromagnetism Kondo screening

Growth of Pb S nanoclusters on specific sites of programmed oligodeoxynucleotides

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Chinese Physics B 2015年第1期24卷 398-403页

作者：陆颖滕翠娟李颖王惠徐春华胡书新李明 Beijing National Laboratory for condensed matter Physics and Key Laboratory of Soft matter Physics Institute of PhysicsChinese Academy of Sciences

We develope a method to synthesize Pb S nanoclusters（NCs） using guanine-containing oligodeoxynucleotides（ODNs）as templates. The NCs on the ODNs are ultra small（ranging from ～ 0.5 nm to 2.1 nm） and luminescent in the visible region. They are characterized by photoluminescence（PL） spectra, transmission electron microscopy（TEM）, and X-ray powder diffraction（XRD）. The ODN–NC complexes can be used as customer-designed fluorophores which do not have the problem of multiple conjugations. The same method enables us to fabricate Pb S quantum dot molecules and connect them into nanowires, expanding their potential applications in molecule electronics and quantum computing.

关键词： Pb S nanoclusters quantum dot molecules oligodeoxynucleotides photoluminescence