The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagne...The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-To superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y 〉 0.06 and the conventional Fermi liquid is restored, while the low-T,, phase remains robust against Sb inlpurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system.展开更多
We propose a surface plasmon(SP) structure in electrically pumped multiple graphene-layer(MGL), and calculate the functions of dynamic conductivity and absorption coefficient. Meanwhile, the dependences of absorption ...We propose a surface plasmon(SP) structure in electrically pumped multiple graphene-layer(MGL), and calculate the functions of dynamic conductivity and absorption coefficient. Meanwhile, the dependences of absorption coefficient on different factors are simulated. SP can get gain when absorption coefficient is negative, and the SP gain can be enhanced by lowering temperature, applying high bias voltage and choosing the graphene with proper layer number and long momentum relaxation time. The study on SP gain is hopeful to be used in amplifiers and graphene-based plasmon devices.展开更多
基金This work was supported by tile National Natural Science Foundation of China （Grant Nos. U1432135, 11674054, 11474080, and 11611140101） and the Scientific Research Foundation of Graduate School of Southeast University （Grant No. YBJJ1621）. X. Xu would also like to acknowledge the National Key Basic Research Program of China （Grant No. 2014CB648400） and the support from the Distinguished Young Scientist Funds of Zhejiang Province （No. LR14A040001）.
文摘The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-To superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y 〉 0.06 and the conventional Fermi liquid is restored, while the low-T,, phase remains robust against Sb inlpurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system.
基金supported by the National Natural Science Foundation of China(No.61001018)the Natural Science Foundation of Shandong Province of China(No.ZR2012FM011)+3 种基金the Project of Shandong Province Higher Educational Science and Technology Program(No.J11LG20)the Qingdao Science&Technology Project(No.11-2-4-4-(8)-jch)the Qingdao Economic & Technical Development Zone Science & Technology Project(No.2013-1-64)the Shandong University of Science and Technology Foundation in China(No.YC140108)
文摘We propose a surface plasmon(SP) structure in electrically pumped multiple graphene-layer(MGL), and calculate the functions of dynamic conductivity and absorption coefficient. Meanwhile, the dependences of absorption coefficient on different factors are simulated. SP can get gain when absorption coefficient is negative, and the SP gain can be enhanced by lowering temperature, applying high bias voltage and choosing the graphene with proper layer number and long momentum relaxation time. The study on SP gain is hopeful to be used in amplifiers and graphene-based plasmon devices.
