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CN 11-5639/O4
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All Express Letters

Doping Mn into (Li1-xFex)OHFe1-ySe superconducting crystals via ion-exchange and ion-release/introduction syntheses Hot!

Huaxue Zhou(周花雪), Shunli Ni(倪顺利), Jie Yuan(袁洁), Jun Li(李军), Zhongpei Feng(冯中沛), Xingyu Jiang(江星宇), Yulong Huang(黄裕龙), Shaobo Liu(刘少博), Yiyuan Mao(毛义元), Fang Zhou(周放), Kui Jin(金魁), Xiaoli Dong(董晓莉), Zhongxian Zhao(赵忠贤)
Chin. Phys. B, 2017, 26 (5): 057402 doi: 10.1088/1674-1056/26/5/057402
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We report the success in introducing Mn into (Li1-xFex)OHFe1-ySe superconducting crystals by applying two different hydrothermal routes, ion exchange (1-step) and ion release/introduction (2-step). The micro-region x-ray diffraction and energy dispersive x-ray spectroscopy analyses indicate that Mn has been doped into the lattice, and its content in the 1-step fabricated sample is higher than that in the 2-step one. Magnetic susceptibility and electric transport properties reveal that Mn doping influences little on the superconducting transition, regardless of 1-step or 2-step routes. By contrast, the characteristic temperature T*, at which the negative Hall coefficient reaches its minimum, is significantly reduced by Mn doping. This implies that the hole carriers contribution is obviously modified, and hence the hole band might have no direct relationship with the superconductivity in (Li1-xFex)OHFe1-ySe superconductors. Our present hydrothermal methods of ion exchange and ion release/introduction provide an efficient way for elements substitution/doping into (Li1-xFex)OHFe1-ySe superconductors, which will promote the in-depth investigations on the role of multiple electron and hole bands and their interplay with the high-temperature superconductivity in the FeSe-based superconductors.

Bow shocks formed by a high-speed laser-driven plasma cloud interacting with a cylinder obstacle Hot!

Yan-Fei Li(李彦霏), Yu-Tong Li(李玉同), Da-Wei Yuan(袁大伟), Fang Li(李芳), Bao-Jun Zhu(朱保君), Zhe Zhang(张喆), Jia-Yong Zhong(仲佳勇), Bo Han(韩波), Hui-Gang Wei(魏会冈), Xiao-Xing Pei(裴晓星), Jia-Rui Zhao(赵家瑞), Chang Liu(刘畅), Xiao-Xia Yuan(原晓霞), Guo-Qian Liao(廖国前), Yong-Joo Rhee, Xin Lu(鲁欣), Neng Hua(华能), Bao-Qiang Zhu(朱宝强), Jian-Qiang Zhu(朱健强), Zhi-Heng Fang(方智恒), Xiu-Guang Huang(黄秀光), Si-Zu Fu(傅思祖), Gang Zhao(赵刚), Jie Zhang(张杰)
Chin. Phys. B, 2017, 26 (5): 055202 doi: 10.1088/1674-1056/26/5/055202
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A bow shock is formed in the interaction of a high-speed laser-driven plasma cloud with a cylinder obstacle. Its temporal and spatial structures are observed by shadowgraphy and interferometry. The width of the shock transition region is ~ 50 μm, comparable to the ion-ion collision mean free path, which indicates that collision is dominated in the shock probably. The Mach-number of the ablating plasma cloud is ~ 15 at first, and decreases with time resulting in a changing shock structure. A two-dimension hydrodynamics code, USim, is used to simulate the interaction process. The simulated shocks can well reproduce the observed.

Superconductivity in self-flux-synthesized single crystalline R2Pt3Ge5(R = La, Ce, Pr) Hot!

Q Sheng(盛琪), J Zhang(张建), K Huang(黄百畅), Z Ding(丁兆峰), X Peng(彭小冉), C Tan(谭程), L Shu(殳蕾)
Chin. Phys. B, 2017, 26 (5): 057401 doi: 10.1088/1674-1056/26/5/057401
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In order to study the basic superconductivity properties of Pr2Pt3Ge5, we synthesized the single crystalline samples by the Pt-Ge self-flux method. R2Pt3Ge5 (R = La, Ce) were also grown for a systematic study. Zero-resistivity was observed in both the La- and Pr-based samples below the reported superconducting transition temperatures. However, magnetic susceptibility measurements showed low superconductivity volume fractions in both La2Pt3Ge5 and Pr2Pt3Ge5 (less than 2%). Ce2Pt3Ge5 did not show any signature of superconductivity. From the specific heat measurements, we did not observe a superconducting transition peak in Pr2Pt3Ge5, suggesting that it is not a bulk superconductor. The magnetic susceptibility and heat capacity measurements revealed two antiferromagnetic (AFM) orders in Pr2Pt3Ge5 at TN1 = 4.2 K and TN2=3.5 K, as well as a single AFM transition at TN = 3.8 K in Ce2Pt3Ge5.

Two-dimensional polyaniline nanosheets via liquid-phase exfoliation Hot!

Su-Na Fan(范苏娜), Ren-Wei Liu(刘仁威), Rui-Song Ma(马瑞松), Shan-Sheng Yu(于陕升), Ming Li(李明), Wei-Tao Zheng(郑伟涛), Shu-Xin Hu(胡书新)
Chin. Phys. B, 2017, 26 (4): 048102 doi: 10.1088/1674-1056/26/4/048102
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Two-dimensional (2D) organic nanomaterials are fascinating because of their unique properties and pentential applications in future optoelectronic devices. Polyaniline (PANI) has attracted much attention for its high conductivity, good environmental stability and unusual doping chemistry. We report on liquid-phase exfoliation of layered PANI films grown by electrochemical polymerization. Atomic force microscopy images demonstrate that few- or even mono-layer PANI nanosheets can be fabricated. The PANI nanosheets can be transferred onto a variety of surfaces, providing a promising route to their incorporation into a variety of devices for further studies and various applications.

DEM simulation of granular segregation in two-compartment system under zero gravity Hot!

Wenguang Wang(王文广), Zhigang Zhou(周志刚), Jin Zong(宗谨), Meiying Hou(厚美瑛)
Chin. Phys. B, 2017, 26 (4): 044501 doi: 10.1088/1674-1056/26/4/044501
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In this paper, granular segregation in a two-compartment cell in zero gravity is studied numerically by DEM simulation. In the simulation using a virtual window method we find a non-monotonic flux, a function which governs the segregation. A parameter is used to quantify the segregation. The effect of three parameters: the total number of particles N, the excitation strength Γ, and the position of the window coupling the two compartments, on the segregation and the waiting time τ are investigated. It is found that the segregation observed in zero gravity exists and does not depend on the excitation strength Γ. The waiting time τ, however, depends strongly on Γ: the higher the Γ, the lower the waiting time τ. The simulation results are important in guiding the SJ-10 satellite microgravity experiments.

Tunable second harmonic generation from a Kerr-lens mode-locked Yb: YCa4O(BO3)3 femtosecond laser Hot!

Zi-Ye Gao(高子叶), Jiang-Feng Zhu(朱江峰), Zheng-Mao Wu(吴正茂), Zhi-Yi Wei(魏志义), Hao-Hai Yu(于浩海), Huai-Jin Zhang(张怀金), Ji-Yang Wang(王继扬)
Chin. Phys. B, 2017, 26 (4): 044202 doi: 10.1088/1674-1056/26/4/044202
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We experimentally demonstrated a diode-pumped Kerr-lens mode-locked femtosecond (fs) laser with a self-frequency doubling Yb:YCa4O(BO3)3 crystal. Sub-40 fs laser pulses were directly generated from the oscillator without extracavity compression. The central wavelength was tunable from 1039 nm to 1049 nm with a typical bandwidth of 35 nm and an average output power of 53 mW. For the first time, a self-frequency doubled second harmonic green laser with tunable range from 519 nm to 525 nm was observed.

Direct loading of atoms from a macroscopic quadrupole magnetic trap into a microchip trap Hot!

Jun Cheng(程俊), Jing-fang Zhang(张敬芳), Xin-ping Xu(许忻平), Hai-chao Zhang(张海潮), Yu-zhu Wang(王育竹)
Chin. Phys. B, 2017, 26 (3): 033701 doi: 10.1088/1674-1056/26/3/033701
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We demonstrate the direct loading of cold atoms into a microchip 2-mm Z-trap, where the evaporative cooling can be performed efficiently, from a macroscopic quadrupole magnetic trap with a high loading efficiency. The macroscopic quadrupole magnetic trap potential is designed to be moveable by controlling the currents of the two pairs of anti-Helmholtz coils. The cold atoms are initially prepared in a standard six-beam magneto-optical trap and loaded into the macroscopic quadrupole magnetic trap, and then transported to the atom chip surface by moving the macroscopic trap potential. By means of a three-dimensional absorption imaging system, we are able to optimize the position alignment of the atom cloud in the macroscopic trap and the microchip Z-shaped wire. Consequently, with a proper magnetic transfer scheme, we load the cold atoms into the microchip Z-trap directly and efficiently. The loading efficiency is measured to be about 50%. This approach can be used to generate appropriate ultracold atoms sources, for example, for a magnetically guided atom interferometer based on atom chip.

Transparent conducting indium-tin-oxide (ITO) film as full front electrode in III-V compound solar cell Hot!

Pan Dai(代盼), Jianya Lu(卢建娅), Ming Tan(谭明), Qingsong Wang(王青松), Yuanyuan Wu(吴渊渊), Lian Ji(季莲), Lifeng Bian(边历峰), Shulong Lu(陆书龙), Hui Yang(杨辉)
Chin. Phys. B, 2017, 26 (3): 037305 doi: 10.1088/1674-1056/26/3/037305
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The application of transparent conducting indium-tin-oxide (ITO) film as full front electrode replacing the conventional bus-bar metal electrode in III-V compound GaInP solar cell was proposed. A high-quality, non-rectifying contact between ITO and 10 nm N+-GaAs contact layer was formed, which is benefiting from a high carrier concentration of the terrilium-doped N+-GaAs layer, up to 2×1019 cm-3. A good device performance of the GaInP solar cell with the ITO electrode was observed. This result indicates a great potential of transparent conducting films in the future fabrication of larger area flexible III-V solar cell.

Two-step quantum secure direct communication scheme with frequency coding Hot!

Xue-Liang Zhao(赵学亮), Jun-Lin Li(李俊林), Peng-Hao Niu(牛鹏皓), Hong-Yang Ma(马鸿洋), Dong Ruan(阮东)
Chin. Phys. B, 2017, 26 (3): 030302 doi: 10.1088/1674-1056/26/3/030302
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Quantum secure direct communication (QSDC) is an important branch of quantum cryptography. It can transmit secret information directly without establishing a key first, unlike quantum key distribution which requires this precursory event. Here we propose a QSDC scheme by applying the frequency coding technique to the two-step QSDC protocol, which enables the two-step QSDC protocol to work in a noisy environment. We have numerically simulated the performance of the protocol in a noisy channel, and the results show that the scheme is indeed robust against channel noise and loss. We also give an estimate of the channel noise upper bound.

Ballistic transport and quantum interference in InSb nanowire devices Hot!

Sen Li(李森), Guang-Yao Huang(黄光耀), Jing-Kun Guo(郭景琨), Ning Kang(康宁), Philippe Caroff, Hong-Qi Xu(徐洪起)
Chin. Phys. B, 2017, 26 (2): 027305 doi: 10.1088/1674-1056/26/2/027305
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An experimental realization of a ballistic superconductor proximitized semiconductor nanowire device is a necessary step towards engineering topological quantum electronics. Here, we report on ballistic transport in InSb nanowires grown by molecular-beam epitaxy contacted by superconductor electrodes. At an elevated temperature, clear conductance plateaus are observed at zero magnetic field and in agreement with calculations based on the Landauer formula. At lower temperature, we have observed characteristic Fabry-Pérot patterns which confirm the ballistic nature of charge transport. Furthermore, the magnetoconductance measurements in the ballistic regime reveal a periodic variation related to the Fabry-Pérot oscillations. The result can be reasonably explained by taking into account the impact of magnetic field on the phase of ballistic electron's wave function, which is further verified by our simulation. Our results pave the way for better understanding of the quantum interference effects on the transport properties of InSb nanowires in the ballistic regime as well as developing of novel device for topological quantum computations.

New progress on beam availability and reliability of PKU high intensity CW proton ECR ion source Hot!

Shi-Xiang Peng(彭士香), Ai-Lin Zhang(张艾霖), Hai-Tao Ren(任海涛), Yuan Xu(徐源), Tao Zhang(张滔), Jing-Feng Zhang(张景丰), Jia-Mei Wen(温佳美), Zhi-Yu Guo(郭之虞), Jia-Er Chen(陈佳洱)
Chin. Phys. B, 2017, 26 (2): 025206 doi: 10.1088/1674-1056/26/2/025206
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The stability and reliability of an ion source and its beam availability are extremely significant for any accelerator, especially for those high current long term CW operation ones like ADS. Although the first high quality 306-hours continuous wave (CW) operating curve at 50 mA@35 keV has been successfully obtained with a standard compact 2.45 GHz ECR ion source at Peking University (PKU), but the uncertainties that caused beam trips before are unacceptable during an accelerator real operation and should be eliminated. Meanwhile, no permission will be given when the beam power is upgraded from 50 mA@35 keV to 50 mA@50 keV. To improve the PKU CW proton source quality, several upgrades were done recently. After those improvements, a new long term CW proton beam experiment at 50 mA@50 keV was carried out in June 2016. The total running time is 300.5 hours, including near 6 hours ion source preparation and 294 hours non-disturb continuous operation. Within the continuous 13 days operation, no beam-off happened, no spark was observed, no beam drop appeared, no interrupting action was needed, and only a few beam fluctuations caused by the air conditional failure occurred. Beam availability and reliability within the 294 hours is 100%. The root-mean-square (RMS) emittance of this 50 mA@50 keV CW proton beam is about 0.186 π.mm.mrad. A careful inspection of the ion source was done after this long term operation and no obvious damage was found. The restart experimental results obtained after the ion source inspection prove the high repeatability of PKU PMECRIS. In addition, a 130-mA H+ beam was obtained at 50 kV with duty factor of 10% (100 Hz/1 ms) with this source. Details will be presented in this paper.

Highly conductive and transparent carbon nanotube-based electrodes for ultrathin and stretchable organic solar cells Hot!

Qingxia Fan(范庆霞), Qiang Zhang(张强), Wenbin Zhou(周文斌), Feng Yang(杨丰), Nan Zhang(张楠), Shiqi Xiao(肖仕奇), Xiaogang Gu(谷孝刚), Zhuojian Xiao(肖卓建), Huiliang Chen(陈辉亮), Yanchun Wang(王艳春), Huaping Liu(刘华平), Weiya Zhou(周维亚)
Chin. Phys. B, 2017, 26 (2): 028801 doi: 10.1088/1674-1056/26/2/028801
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In this work, we have presented a freestanding and flexible CNT-based film with sheet resistance of 60 Ω/□ and transmittance of 82% treated by nitric acid and chloroauric acid in sequence. Based on modified CNT film as a transparent electrode, we have demonstrated an ultrathin, flexible organic solar cell (OSC) fabricated on 2.5-μm PET substrate. The efficiency of OSC, combined with a composite film of poly (3-hexylthiophene) (P3HT) and phenyl-C61 butyric acid methyl ester (PCBM) as an active layer and with a thin layer of methanol soluble biuret inserted between the photoactive layer and the cathode, can be up to 2.74% which is approximate to that of the reference solar cell fabricated with ITO-coated glass (2.93%). Incorporating the as-fabricated ITO-free OSC with pre-stretched elastomer, 50% compressive deformation can apply to the solar cells. The results show that the as-prepared CNT-based hybrid film with outstanding electrical and optical properties could serve as a promising transparent electrode for low cost, flexible and stretchable OSCs, which will broaden the applications of OSC and generate more solar power than it now does.

Energy sharing induced by the nonlinear interaction Hot!

Yuan Liu(刘渊), Zhifang Feng(冯志芳), Weidong Li(李卫东)
Chin. Phys. B, 2017, 26 (1): 013401 doi: 10.1088/1674-1056/26/1/013401
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Strong energy sharing is shown by numerically investigating coupled multi-component Bose-Einstein condensates (BECs) with a harmonic trap to simulate the Fermi-Pasta-Ulam model (FPU). For two-component BECs, the energy exchanging between each part, from regular, quantum beating to complete energy sharing, is explored by simulating their Husimi distributions, the time evolution of energies and the statistical entropy. Meanwhile, in the three-component case, a more complex energy sharing behavior is reported and a strong energy sharing is found.

Implementation of LDA+Gutzwiller with Newton's method Hot!

Jian Zhang(张健), Ming-Feng Tian(田明锋), Guang-Xi Jin(金光希), Yuan-Feng Xu(徐远锋), Xi Dai(戴希)
Chin. Phys. B, 2017, 26 (1): 017103 doi: 10.1088/1674-1056/26/1/017103
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In order to calculate the electronic structure of correlated materials, we propose implementation of the LDA+Gutzwiller method with Newton's method. The self-consistence process, efficiency and convergence of calculation are improved dramatically by using Newton's method with golden section search and other improvement approaches. We compare the calculated results by applying the previous linear mix method and Newton's method. We have applied our code to study the electronic structure of several typical strong correlated materials, including SrVO3, LaCoO3, and La2O3Fe2Se2. Our results fit quite well with the previous studies.

Electron localization of linear symmetric molecular ion H32+ Hot!

Zheng-Mao Jia(贾正茂), Zhi-Nan Zeng(曾志男), Ru-Xin Li(李儒新)
Chin. Phys. B, 2017, 26 (1): 013203 doi: 10.1088/1674-1056/26/1/013203
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Electron localization in the dissociation of the symmetric linear molecular ion H32+ is investigated. The numerical simulation shows that the electron localization distribution is dependent on the central frequency and peak electric field amplitude of the external ultrashort ultraviolet laser pulse. When the electrons of the ground state are excited onto the 2pσ2Σu+ by a one-photon process, most electrons of the dissociation states are localized at the protons on both sides symmetrically. Almost no electron is stabilized at the middle proton due to the odd symmetry of the wave function. With the increase of the frequency of the external ultraviolet laser pulse, the electron localization ratio of the middle proton increases, for more electrons of the ground state are excited onto the higher 3pσ2Σu+ state. 50.9% electrons of all the dissociation events can be captured by the middle Coulomb potential well through optimizing the central frequency and peak electric field amplitude of the ultraviolet laser pulse. Besides, a direct current (DC) electric field can be utilized to control the electron motions of the dissociation states after the excitation of an ultraviolet laser pulse, and 68.8% electrons of the dissociation states can be controlled into the middle proton.

Modulation of intra- and inter-sheet interactions in short peptide self-assembly by acetonitrile in aqueous solution Hot!

Li Deng(邓礼), Yurong Zhao(赵玉荣), Peng Zhou(周鹏), Hai Xu(徐海), Yanting Wang(王延颋)
Chin. Phys. B, 2016, 25 (12): 128704 doi: 10.1088/1674-1056/25/12/128704
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Besides our previous experimental discovery (Zhao Y R, et al. 2015 Langmuir, 31, 12975) that acetonitrile (ACN) can tune the morphological features of nanostructures self-assembled by short peptides KⅢIK (KI4K) in aqueous solution, further experiments reported in this work demonstrate that ACN can also tune the mass of the self-assembled nanostructures. To understand the microscopic mechanism how ACN molecules interfere peptide self-assembly process, we conducted a series of molecular dynamics simulations on a monomer, a cross-β sheet structure, and a proto-fibril of KI4K in pure water, pure ACN, and ACN-water mixtures, respectively. The simulation results indicate that ACN enhances the intra-sheet interaction dominated by the hydrogen bonding (H-bonding) interactions between peptide backbones, but weakens the inter-sheet interaction dominated by the interactions between hydrophobic side chains. Through analyzing the correlations between different groups of solvent and peptides and the solvent behaviors around the proto-fibril, we have found that both the polar and nonpolar groups of ACN play significant roles in causing the opposite effects on intermolecular interactions among peptides. The weaker correlation of the polar group of ACN than water molecule with the peptide backbone enhances H-bonding interactions between peptides in the proto-fibril. The stronger correlation of the nonpolar group of ACN than water molecule with the peptide side chain leads to the accumulation of ACN molecules around the proto-fibril with their hydrophilic groups exposed to water, which in turn allows more water molecules close to the proto-fibril surface and weakens the inter-sheet interactions. The two opposite effects caused by ACN form a microscopic mechanism clearly explaining our experimental observations.

Tunable in-plane spin orientation in Fe/Si (557) film by step-induced competing magnetic anisotropies Hot!

Jin Tang(汤进), Wei He(何为), Yong-Sheng Zhang(张永圣), Yan Li(李岩), Wei Zhang(张伟), Syed Sheraz Ahmad, Xiang-Qun Zhang(张向群), Zhao-Hua Cheng(成昭华)
Chin. Phys. B, 2016, 25 (12): 127501 doi: 10.1088/1674-1056/25/12/127501
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Although the spin-reorientation transition from out-of-plane to in-plane in Fe/Si film is widely reported, the tuning of in-plane spin orientation is not yet well developed. Here, we report the thickness-, temperature- and Cu-adsorption-induced in-plane spin-reorientation transition processes in Fe/Si (557) film, which can be attributed to the coexistence of two competing step-induced uniaxial magnetic anisotropies, i.e., surface magnetic anisotropy with magnetization easy axis perpendicular to the step and volume magnetic anisotropy with magnetization easy axis parallel to the step. For Fe film thickness smaller than 32 monolayer (ML), the magnitudes of two effects under various temperatures are extracted from the thickness dependence of uniaxial magnetic anisotropy. For Fe film thickness larger than 32 ML, the deviation of experimental results from fitting results is understood by the strain-relief-induced reduction of volume magnetic anisotropy. Additionally, the surface and volume magnetic anisotropies are both greatly reduced after covering Cu capping layer on Fe/Si (557) film while no significant influence of NaCl capping layer on step-induced magnetic anisotropies is observed. The experimental results reported here provide various practical methods for manipulating in-plane spin orientation of Fe/Si films and improve the understanding of step-induced magnetic anisotropies.

Microscale vortex laser with controlled topological charge Hot!

Xing-Yuan Wang(王兴远), Hua-Zhou Chen(陈华洲), Ying Li(黎颖), Bo Li(李波), Ren-Min Ma(马仁敏)
Chin. Phys. B, 2016, 25 (12): 124211 doi: 10.1088/1674-1056/25/12/124211
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A microscale vortex laser is a new type of coherent light source with small footprint that can directly generate vector vortex beams. However, a microscale laser with controlled topological charge, which is crucial for virtually any of its application, is still unrevealed. Here we present a microscale vortex laser with controlled topological charge. The vortex laser eigenmode was synthesized in a metamaterial engineered non-Hermitian micro-ring cavity system at exceptional point. We also show that the vortex laser cavity can operate at exceptional point stably to lase under optical pumping. The microscale vortex laser with controlled topological charge can serve as a unique and general building block for next-generation photonic integrated circuits and coherent vortex beam sources. The method we used here can be employed to generate lasing eigenmode with other complex functionalities.

High performance photodetectors based on high quality InP nanowires Hot!

Yan-Kun Yang(杨燕琨), Tie-Feng Yang(杨铁锋), Hong-Lai Li(李洪来), Zhao-Yang Qi(祁朝阳), Xin-Liang Chen(陈新亮), Wen-Qiang Wu(吴文强), Xue-Lu Hu(胡学鹿), Peng-Bin He(贺鹏斌), Ying Jiang(蒋英), Wei Hu(胡伟), Qing-Lin Zhang(张清林), Xiu-Juan Zhuang(庄秀娟), Xiao-Li Zhu(朱小莉), An-Lian Pan(潘安练)
Chin. Phys. B, 2016, 25 (11): 118106 doi: 10.1088/1674-1056/25/11/118106
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In this paper, small diameter InP nanowires with high crystal quality were synthesized through a chemical vapor deposition method. Benefitting from the high crystallinity and large specific surface area of InP nanowires, the simply constructed photodetector demonstrates a high responsivity of up to 1170 A·W-1 and an external quantum efficiency of 2.8×105% with a fast rise time of 110 ms and a fall time of 130 ms, even at low bias of 0.1 V. The effect of back-gate voltage on photoresponse of the device was systematically investigated, confirming that the photocurrent dominates over thermionic and tunneling currents in the whole operation. A mechanism based on energy band theory at the junction between metal and semiconductor was proposed to explain the back-gate voltage dependent performance of the photodetectors. These convincing results indicate that fine InP nanowires will have a brilliant future in smart optoelectronics.

Spatially resolved gap closing in single Josephson junctions constructed on Bi2Te3 surface Hot!

Yuan Pang(庞远), Junhua Wang(王骏华), Zhaozheng Lyu(吕昭征), Guang Yang(杨光), Jie Fan(樊洁), Guangtong Liu(刘广同), Zhongqing Ji(姬忠庆), Xiunian Jing(景秀年), Changli Yang(杨昌黎), Li Lu(吕力)
Chin. Phys. B, 2016, 25 (11): 117402 doi: 10.1088/1674-1056/25/11/117402
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Full gap closing is a prerequisite for hosting Majorana zero modes in Josephson junctions on the surface of topological insulators. Previously, we have observed direct experimental evidence of gap closing in Josephson junctions constructed on Bi2Te3 surface. In this paper we report further investigations on the position dependence of gap closing as a function of magnetic flux in single Josephson junctions constructed on Bi2Te3 surface.

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