Nonequilibrium quasiparticle relaxation dynamics in single crystals of hole- and electron-doped BaFe2As2

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	Nonequilibrium quasiparticle relaxation dynamics in single crystals of hole- and electron-doped BaFe2As2
	Torchinsky, DH ; McIver, JW ; Hsieh, D ; Chen, GF ; Luo, JL ; Wang, NL ; Gedik, N
刊名	PHYSICAL REVIEW B
	2011
卷号	84 期号:10
关键词	SUPERCONDUCTORS BA0.6K0.4FE2AS2 LIFETIMES
ISSN号	1098-0121
通讯作者	Torchinsky, DH (reprint author), MIT, Dept Phys, Cambridge, MA 02139 USA.
中文摘要	We report on the nonequilibrium quasiparticle dynamics in BaFe2As2 on both the hole-doped (Ba1-xKxFe2As2)and electron-doped (BaFe2-yCoyAs2) sides of the phase diagram using ultrafast pump-probe spectroscopy. Below T-c, measurements conducted at low photoinjected quasiparticle densities in the optimally and overdoped Ba1-xKxFe2As2 samples reveal two distinct relaxation processes: a fast component whose decay rate increases linearly with excitation density and a slow component with an excitation density independent decay rate. We argue that these two processes reflect the recombination of quasiparticles in the two hole bands through intraband and interband processes. We also find that the thermal recombination rate of quasiparticles increases quadratically with temperature in these samples. The temperature and excitation density dependence of the decays indicates fully gapped hole bands and nodal or very anisotropic electron bands. At higher excitation densities and lower hole dopings, the dependence of the dynamics on quasiparticle density disappears as the data are more readily understood in terms of a model which accounts for the quasiequilibrium temperature attained by the sample. In the BaFe2-yCoyAs2 samples, dependence of the recombination rate on quasiparticle density at low dopings (i.e., y = 0.12) is suppressed upon submergence of the inner hole band and quasiparticle relaxation occurs in a slow, density-independent manner.
收录类别	SCI
资助信息	DOE [DE-FG02-08ER46521]; MRSEC of National Science Foundation [DMR - 0819762]; CAS; MOST of China; NSFC
语种	英语
公开日期	2013-09-24
内容类型	期刊论文
源URL	[http://ir.iphy.ac.cn/handle/311004/49951]
专题	物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文
推荐引用方式 GB/T 7714	Torchinsky, DH,McIver, JW,Hsieh, D,et al. Nonequilibrium quasiparticle relaxation dynamics in single crystals of hole- and electron-doped BaFe2As2[J]. PHYSICAL REVIEW B,2011,84(10).
APA	Torchinsky, DH.,McIver, JW.,Hsieh, D.,Chen, GF.,Luo, JL.,...&Gedik, N.(2011).Nonequilibrium quasiparticle relaxation dynamics in single crystals of hole- and electron-doped BaFe2As2.PHYSICAL REVIEW B,84(10).
MLA	Torchinsky, DH,et al."Nonequilibrium quasiparticle relaxation dynamics in single crystals of hole- and electron-doped BaFe2As2".PHYSICAL REVIEW B 84.10(2011).