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Topological magnon insulator with Dzyaloshinskii–Moriya interaction under the irradiation of light

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Chinese Physics B 2019年第7期28卷 538-541页

作者： Liang Chen School of Physics and Electronic Engineering Taishan University

The topological magnon insulator on a honeycomb lattice with Dzyaloshinskii–Moriya interaction(DMI) is studied under the application of a circularly polarized *** the high-frequency regime, the effective tight-binding model is obtained based on Brillouin–Wigner ***, we study the corresponding Berry curvature and Chern *** the Dirac model, the interplay between a light-induced handedness-dependent effective DMI and intrinsic DMI is discussed.

关键词： magnon light Brillouin–Wigner theory Dzyaloshinskii–Moriya

Limits on light emission from silicon

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Chinese Optics Letters 2009年第4期7卷 268-270页

作者： Peter Würfel Institut für Angewandte Physik Universitt KarlsruheD-76128 KarlsruheGermany

Although silicon is an indirect semiconductor, light emission from silicon is governed by the same gener- alized Planck＇s radiation law as the emission from direct semiconductors. The emission intensity is given by the absorptance of the volume in which there is a difference of the quasi Fermi energies. A difference of the Fermi energies may result h＇om the absorption of external light （photoluminescence） or from the injection of electrons and holes via selective contacts （electroluminescence）. The quantum efficiency may be larger than 0.5 for carrier densities below 10^15 cm^-3. At larger densities, non-radiative recombination, in particular Auger recombination dominates. At all carrier densities, the relation between emission intensity and difference of the quasi Fermi energies is maintained. Since this difference is equal to the voltage of a properly designed solar cell, luminescence is the key indicator of material quality for solar cells.

关键词： Carrier concentration Fermi level light light emission Photoluminescence Semiconducting silicon Silicon

Stimulated Brillouin scattering phase conjugation of light beams carrying orbit angular momentum(Invited Paper)

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Chinese Optics Letters 2017年第3期15卷 21-23页

作者：陈旭东昌成成蒲继雄 Fujian Key Laboratory of light Propagation and Transformation College of Information Science and Engineering Huaqiao University Xiamen 361021 China

We investigate the stimulated Brillouin scattering （SBS） properties of light beams carrying orbit angular momentum （OAM）. The phase conjugation of light beams carrying OAM is experimentally achieved in an SBS mirror with a random phase plate. The spectrum and the pulse width compression of SBS light are measured. It is shown that the phenomena of pulse compression is observed and OAM conservation is confirmed in the SBS process. The OAM transfer from photons to phonons may find potential applications in photon-phonon conversion-based signal-processing schemes by using OAM multiplexing.

关键词： Angular momentum Brillouin scattering light Phonons Photons Signal processing Solid state lasers

Redox active ionic liquid as efficient mediator and solvent for visible light-driven B_(12) catalytic reactions

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Green Energy & Environment 2019年第2期4卷 116-120页

作者： Hisashi Shimakoshi Noriyuki Houfuku Li Chen Yoshio Hisaeda Department of Chemistry and Biochemistry Graduate School of Engineering Kyushu University

The redox active ionic liquid, 1-ethyl-4-(methoxycarbonyl)pyridinium bis(trifluoromethanesulfonyl)amide(RIL), was synthesized from its iodide form by an anion exchange reaction of Li(NTf_2) with viscos liquid(η= 122 cP at 25C) and characterized by NMR, IR, and elemental analysis. The compound showed reversible redox couples at -0.65 V and -1.48 V vs. Ag/AgCl and worked as an electron mediator in the B_(12) complex/[Ru(bpy)_3]Cl_2 photosensitizer catalytic system under visible light irradiation. The catalytic efficiency in the RIL was higher than those in DMF, MeOH, and the redox inactive ionic liquid, 1-butyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)amide.

关键词： Ionic liquid Photosensitizer Redox active Visible light Vitamin B12

Carrier Dynamics Determined by Carrier-Phonon Coupling in InGaN/GaN Multiple Quantum Well Blue light Emitting Diodes

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Chinese Physics Letters 2019年第2期36卷 92-95页

作者： Sheng Cao Xiao-Ming Wu Jun-Lin Liu Feng-Yi Jiang National Institute of LED on Si Substrate Nanchang University

Phonon sidebands in the electrolumiescence(EL) spectra of InGaN/GaN multiple quantum well blue light emitting diodes are investigated. S-shaped injection current dependence of the energy spacing(ES) between the zero-phonon and first-order phonon-assisted luminescence lines is observed in a temperature range of 100–150 *** S-shape is suppressed with increasing temperature from 100 to 150 K, and vanishes at temperature above200 K. The S-shaped injection dependence of ES at low temperatures could be explained by the three stages of carrier dynamics related to localization states:(i) carrier relaxation from shallow into deep localization states,(ii) band filling of shallow and deep localization states, and(iii) carrier overflow from deep to shallow localization states and to higher energy states. The three stages show strong temperature dependence. It is proposed that the fast change of the carrier lifetime with temperature is responsible for the suppression of S-shaped *** proposed mechanisms reveal carrier recombination dynamics in the EL of InGaN/GaN MQWs at various injection current densities and temperatures.

关键词： Carrier Dynamics Determined Carrier-Phonon Coupling InGaN/GaN Multiple Quantum Well Blue light Emitting Diodes

Transport properties of the topological Kondo insulator SmB_6 under the irradiation of light

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Chinese Physics B 2016年第10期25卷 373-377页

作者：朱国宝杨慧敏 Department of Physics and Electronic Engineering Heze University Institute of Theoretical Physics Heze University

In this paper, we study transport properties of the  point in the Brillouin zone of the topological Kondo insulator SmB6under the application of a circularly polarized light. The transport properties at high-frequency regime and lowfrequency regime as a function of the ratio(κ) of the Dresselhaus-like and Rashba-like spin–orbit parameter are studied based on the Floquet theory and Boltzmann equation respectively. The sign of Hall conductivity at high-frequency regime can be reversed by the ratio κ and the amplitude of the light. The amplitude of the current can be enhanced by the ratio κ.Our findings provide a way to control the transport properties of the Dirac materials at low-frequency regime.

关键词： SmB_6 light Flouqet theory Boltzmann equation

Excitation of light-Induced Acoustic Waves in Doped Lithium Niobate Crystals

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Journal of Rare Earths 2006年第Z1期24卷 264-268页

作者： Huang Wei Wu Zhongkang Department of Basic Beijing Institute of Civil Engineering and Architecture Beijing 100044 China Department of Physic Nankai University Tianjin 300071 China

The phenomena of acoustic emission in doped lithium niobate crystals were observed in the process of light-induced quasi-breakdown. It is found that the ultrasonic waves introduce into the crystal have been modulated by the low frequency acoustic waves. Its frequency increases with the rise of the intensity of incident light and its jump period of breakdown is the same as that of the photovoltaic current Ic, the change of light-induced refractive index Δn and the diffracted light intensity L. This effect was explained with the interaction of the three waves and resonant state theory. The experimental results and the theoretical analysis are in conformity.

关键词： photovoltaic current space charge wave light induced quasi-breakdown light induced acoustic effect

Creation of passivated Nb/N p-n co-doped ZnO nanoparticles and their enhanced photocatalytic performance under visible light illumination

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Journal of Materials Science & Technology 2019年第4期35卷 610-614页

作者： Shuang Gao Weiyi Yang Jun Xiao Bo Li Qi Li Division of Energy and Environment Graduate School at ShenzhenTsinghua University Environment Functional Materials Division Shenyang National Laboratory for Materials ScienceInstitute of Metal ResearchChinese Academy of Sciences

Passivated niobium/nitrogen(Nb-N) p-n co-doped zinc oxide nanoparticles were created by a simple precipitation process with in-situ self-formed NaCl "cage" to confine the nanoparticle growth followed by the heat treatment in a flow of ammonia gas. Enhanced optical absorbance into the visible light region was observed in the Nb/N co-doped ZnO nanoparticle photocatalyst due to the Nb/N co-doping *** demonstrated a largely enhanced photocatalytic performance in the disinfection of Escherichia coli bacteria under visible light illumination, which could be attributed to the passivated co-doping of NbN to suppress the photogenerated charge carrier recombination on dopants. This robust approach for passivated p-n co-doping may also be applied to other material systems for a wide range of technical applications.

关键词： Zinc oxide Nanoparticles Passivated Nb/N p-n Co-doping Photocatalyst Visible light

Optically noninvasive measurement of the light transport properties of human meridians

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Chinese Optics Letters 2008年第12期6卷 928-931页

作者：谢树森杨洪钦郭周义李晖刘颂豪 Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education Fujian Provincial Key Laboratory of Photonic Technology Institute of Laser and Optoelectronics TechnologyFujian Normal University Laboratory of Photonic Traditional Chinese Medicine and Key Laboratory of Laser Life Science of Ministry of Education South China Normal University

To confirm the existence and properties of human meridians, the optical transport properties along the pericardium meridian and tissues around the pericardium meridian are studied noninvasively on twenty healthy volunteers in vivo and then compared with each other. Our study shows that the light propagating along the meridian and non-meridian directions both conform to the Beer＇s exponential attenuation law. However, statistical analysis of the results suggests that the optical transport properties of human meridian differ from those of the surrounding tissues over a low modulated frequency range （P 〈 0.01）, and light attenuation along the pericardium meridian is significantly less than that along the non-meridian direction. These findings not only indicate the existence of acupuncture meridian from the point of view of biomedical optics, but also shed new light on an approach to investigation of human meridians.

关键词： Beverages Histology light