Photoinduced conductivity dynamics studies of MgB2 thin films

被引:13
作者
Demsar, J
Averitt, RD
Taylor, AJ
Kang, WN
Kim, HJ
Choi, EM
Lee, SI
机构
[1] Los Alamos Natl Lab, Los Alamos, NM 87545 USA
[2] Pohang Univ Sci & Technol, Dept Phys, Natl Creat Res Initiat Ctr Supercond, Pohang 790784, South Korea
来源
INTERNATIONAL JOURNAL OF MODERN PHYSICS B | 2003年 / 17卷 / 18-20期
关键词
MgB2; Terahertz spectroscopy; time-resolved spectroscopy;
D O I
10.1142/S0217979203021605
中图分类号
O59 [应用物理学];
学科分类号
摘要
We present the first direct studies of photoinduced Cooper-pair breaking and subsequent superconducting state recovery dynamics by means of femtosecond time-resolved optical-pump terahertz probe spectroscopy focusing on the superconducting state recovery dynamics in MgB2. The superconducting state recovery proceeds on the timescale of several hundred picoseconds and shows a strong temperature dependence. In particular, upon increasing the temperature the recovery time first decreases, reaches a minimum, followed by a quasi-divergence upon further increasing the temperature towards T-c. Moreover, the recovery time shows virtually no intensity dependence, even though the photoexcitation fluence is changed by over an order of magnitude. This suggests that pair recovery is goverend by a phonon-bottleneck mechanism, where the lifetime of high energy phonons (hw > 2Delta) is governed by their anharmonicity.
引用
收藏
页码:3675 / 3681
页数:7
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