Using the Keldysh-Green function,we present a theoretical study on the electron transport properties of two coupled quantum dots under optical pumping. Plateaus in the I-V curve and resonant peaks in the transmission ...Using the Keldysh-Green function,we present a theoretical study on the electron transport properties of two coupled quantum dots under optical pumping. Plateaus in the I-V curve and resonant peaks in the transmission coefficient occur and can be explained by the local electron density of states in the quantum dots. The effects of the optical pumping frequency and intensity on the transport properties of the system are also discussed. The electron dynamical localization phenomenon occurs when the optical pumping frequency is equal to the discrete hole energy level. This result can be used to realize optical control switches.展开更多
TG156.99 2001053185陶瓷表面激光诱导局域化学镀覆金属镍的研究=Experimental study of laser-induced deposition of nickel surface of ceramic[刊,中]/黄妙良,林煜,林建明(华侨大学材料物理化学研究所.福建,泉州(362011))//激光杂志...TG156.99 2001053185陶瓷表面激光诱导局域化学镀覆金属镍的研究=Experimental study of laser-induced deposition of nickel surface of ceramic[刊,中]/黄妙良,林煜,林建明(华侨大学材料物理化学研究所.福建,泉州(362011))//激光杂志.—2000,21(6).—42-43利用1079.5 nm Nd:YAP激光作诱导光源,普通陶瓷作为基体,研究了激光功率、辐照时间、镀液组份。展开更多
The local structure and dynamics of impurities Fe,Al and Mn in beryllium were investigated on an atomic scale using ab initio molecular dynamics and statistical physics methods.The analysis of the radial distribution ...The local structure and dynamics of impurities Fe,Al and Mn in beryllium were investigated on an atomic scale using ab initio molecular dynamics and statistical physics methods.The analysis of the radial distribution function centered on impurity atoms shows that the density of beryllium atoms around Fe and Mn is 8.4%and 8.6%higher than that around Al,respectively.The statistics of the measure square displacement of impurity atoms show that the diffusion coefficients of Al atoms are 114%and 133%larger than that of Fe and Mn atoms in the melt beryllium,respectively.Statistical analysis of velocity autocorrelation function of impurity atom shows that Fe and Mn atoms collide strongly with beryllium atoms in the first coordination layer,indicating that they are tightly surrounded and bound by the surrounding beryllium atoms in the central position,while the beryllium atoms around Al are loosely arranged and have weak binding forces with Al.The analysis of the activity coefficients of the impurities shows that when Fe or Mn enters the melt beryllium,it reduces the free energy of the system,whereas when Al enters,it increases the system energy.In summary,the interatomic force of BeAl is weak,so they do not form intermetallic compounds,and Al diffuses quickly in beryllium.While BeFe and BeMn have strong interatomic forces,and tend to form more BeFe and BeMn bonds to reduce the free energy of the system,so Fe and Mn diffuse slowly in beryllium.Ab initio molecular dynamics can be used to forecast the best experimental temperature for the vacuum distillation of beryllium.展开更多
文摘Using the Keldysh-Green function,we present a theoretical study on the electron transport properties of two coupled quantum dots under optical pumping. Plateaus in the I-V curve and resonant peaks in the transmission coefficient occur and can be explained by the local electron density of states in the quantum dots. The effects of the optical pumping frequency and intensity on the transport properties of the system are also discussed. The electron dynamical localization phenomenon occurs when the optical pumping frequency is equal to the discrete hole energy level. This result can be used to realize optical control switches.
文摘TG156.99 2001053185陶瓷表面激光诱导局域化学镀覆金属镍的研究=Experimental study of laser-induced deposition of nickel surface of ceramic[刊,中]/黄妙良,林煜,林建明(华侨大学材料物理化学研究所.福建,泉州(362011))//激光杂志.—2000,21(6).—42-43利用1079.5 nm Nd:YAP激光作诱导光源,普通陶瓷作为基体,研究了激光功率、辐照时间、镀液组份。
基金National Natural Science Foundation of China(12104425)Supported by State Key Laboratory of Special Rare Metal Materials,Northwest Rare Metal Materials Research Institute Ningxia Co.,Ltd(SKL2020K001)。
文摘The local structure and dynamics of impurities Fe,Al and Mn in beryllium were investigated on an atomic scale using ab initio molecular dynamics and statistical physics methods.The analysis of the radial distribution function centered on impurity atoms shows that the density of beryllium atoms around Fe and Mn is 8.4%and 8.6%higher than that around Al,respectively.The statistics of the measure square displacement of impurity atoms show that the diffusion coefficients of Al atoms are 114%and 133%larger than that of Fe and Mn atoms in the melt beryllium,respectively.Statistical analysis of velocity autocorrelation function of impurity atom shows that Fe and Mn atoms collide strongly with beryllium atoms in the first coordination layer,indicating that they are tightly surrounded and bound by the surrounding beryllium atoms in the central position,while the beryllium atoms around Al are loosely arranged and have weak binding forces with Al.The analysis of the activity coefficients of the impurities shows that when Fe or Mn enters the melt beryllium,it reduces the free energy of the system,whereas when Al enters,it increases the system energy.In summary,the interatomic force of BeAl is weak,so they do not form intermetallic compounds,and Al diffuses quickly in beryllium.While BeFe and BeMn have strong interatomic forces,and tend to form more BeFe and BeMn bonds to reduce the free energy of the system,so Fe and Mn diffuse slowly in beryllium.Ab initio molecular dynamics can be used to forecast the best experimental temperature for the vacuum distillation of beryllium.
